1829 |
Maximum XOR for Each Query |
Solution |
|
Medium |
Bit Manipulation |
1828 |
Queries on Number of Points Inside a Circle |
Solution |
|
Medium |
Math |
1827 |
Minimum Operations to Make the Array Increasing |
Solution |
|
Easy |
Array, Greedy |
1823 |
Find the Winner of the Circular Game |
Solution |
|
Medium |
Array |
1822 |
Sign of the Product of an Array |
Solution |
|
Easy |
Math |
1817 |
Finding the Users Active Minutes |
Solution |
|
Medium |
HashTable |
1816 |
Truncate Sentence |
Solution |
|
Easy |
String |
1814 |
Count Nice Pairs in an Array |
Solution |
|
Medium |
Array, HashTable |
1813 |
Sentence Similarity III |
Solution |
๐บ |
Medium |
String |
1812 |
Determine Color of a Chessboard Square |
Solution |
|
Easy |
String |
1807 |
Evaluate the Bracket Pairs of a String |
Solution |
|
Medium |
HashTable, String |
1806 |
Minimum Number of Operations to Reinitialize a Permutation |
Solution |
|
Medium |
Array, Greedy |
1805 |
Number of Different Integers in a String |
Solution |
|
Medium |
String |
1800 |
Maximum Ascending Subarray Sum |
Solution |
|
Easy |
Two Pointers |
1797 |
Design Authentication Manager |
Solution |
|
Medium |
HashTable, Design |
1796 |
Second Largest Digit in a String |
Solution |
|
Easy |
String |
1792 |
Maximum Average Pass Ratio |
Solution |
|
Medium |
Heap |
1791 |
Find Center of Star Graph |
Solution |
|
Medium |
Graph |
1790 |
Check if One String Swap Can Make Strings Equal |
Solution |
|
Easy |
String |
1785 |
Minimum Elements to Add to Form a Given Sum |
Solution |
|
Medium |
Greedy |
1784 |
Check if Binary String Has at Most One Segment of Ones |
Solution |
|
Easy |
Greedy |
1781 |
Sum of Beauty of All Substrings |
Solution |
|
Medium |
HashTable, String |
1780 |
Check if Number is a Sum of Powers of Three |
Solution |
|
Medium |
Math, Backtracking, Recursion |
1779 |
Find Nearest Point That Has the Same X or Y Coordinate |
Solution |
|
Easy |
Array |
1775 |
Equal Sum Arrays With Minimum Number of Operations |
Solution |
|
Medium |
Greedy |
1774 |
Closest Dessert Cost |
Solution |
|
Medium |
Greedy |
1773 |
Count Items Matching a Rule |
Solution |
๐บ |
Easy |
Array, String |
1772 |
Sort Features by Popularity |
Solution |
๐บ |
Medium |
HashTable, Sort |
1769 |
Minimum Number of Operations to Move All Balls to Each Box |
Solution |
|
Medium |
Array, Greedy |
1768 |
Merge Strings Alternately |
Solution |
|
Easy |
String |
1765 |
Map of Highest Peak |
Solution |
|
Medium |
BFS, Graph |
1764 |
Form Array by Concatenating Subarrays of Another Array |
Solution |
|
Medium |
Array, Greedy |
1763 |
Longest Nice Substring |
Solution |
|
Easy |
String |
1759 |
Count Number of Homogenous Substrings |
Solution |
|
Medium |
String ,Greedy |
1758 |
Minimum Changes To Make Alternating Binary String |
Solution |
|
Easy |
Greedy, Array |
1756 |
Design Most Recently Used Queue |
Solution |
|
Medium |
Array, Design, Dequeue |
1754 |
Largest Merge Of Two Strings |
Solution |
|
Medium |
Greedy, Suffix Array |
1753 |
Maximum Score From Removing Stones |
Solution |
|
Medium |
Math, Heap |
1752 |
Check if Array Is Sorted and Rotated |
Solution |
|
Easy |
Array |
1750 |
Minimum Length of String After Deleting Similar Ends |
Solution |
|
Medium |
Two Pointers |
1749 |
Maximum Absolute Sum of Any Subarray |
Solution |
|
Medium |
Greedy |
1748 |
Sum of Unique Elements |
Solution |
|
Easy |
Array, HashTable |
1746 |
Maximum Subarray Sum After One Operation |
Solution |
|
Medium |
DP |
1745 |
Palindrome Partitioning IV |
Solution |
|
Hard |
String, DP |
1743 |
Restore the Array From Adjacent Pairs |
Solution |
|
Medium |
Greedy |
1742 |
Maximum Number of Balls in a Box |
Solution |
|
Easy |
Array |
1736 |
Latest Time by Replacing Hidden Digits |
Solution |
|
Easy |
String, Greedy |
1733 |
Minimum Number of People to Teach |
Solution |
|
Medium |
Array, Greedy |
1732 |
Find the Highest Altitude |
Solution |
|
Easy |
Array |
1727 |
Largest Submatrix With Rearrangements |
Solution |
|
Medium |
Greedy, Sort |
1726 |
Tuple with Same Product |
Solution |
๐บ |
Medium |
Array |
1725 |
Number Of Rectangles That Can Form The Largest Square |
Solution |
|
Easy |
Greedy |
1721 |
Swapping Nodes in a Linked List |
Solution |
|
Medium |
LinkedList |
1720 |
Decode XORed Array |
Solution |
|
Easy |
Bit Manipulation |
1718 |
Construct the Lexicographically Largest Valid Sequence |
Solution |
|
Medium |
Backtracking, Recursion |
1717 |
Maximum Score From Removing Substrings |
Solution |
๐บ |
Medium |
Greedy |
1716 |
Calculate Money in Leetcode Bank |
Solution |
|
Easy |
Math, Greedy |
1711 |
Count Good Meals |
Solution |
|
Medium |
Array, HashTable, Two Pointers |
1710 |
Maximum Units on a Truck |
Solution |
|
Easy |
Greedy, Sort |
1708 |
Largest Subarray Length K |
Solution |
|
Easy |
Array, Greedy |
1705 |
Maximum Number of Eaten Apples |
Solution |
|
Medium |
Heap, Greedy |
1704 |
Determine if String Halves Are Alike |
Solution |
|
Easy |
String |
1700 |
Number of Students Unable to Eat Lunch |
Solution |
|
Easy |
Array |
1694 |
Reformat Phone Number |
Solution |
|
Easy |
String |
1690 |
Stone Game VII |
Solution |
|
Medium |
DP |
1688 |
Count of Matches in Tournament |
Solution |
|
Easy |
Backtracking |
1686 |
Stone Game VI |
Solution |
|
Medium |
Greedy |
1685 |
Sum of Absolute Differences in a Sorted Array |
Solution |
๐บ |
Medium |
Math, Greedy |
1684 |
Count the Number of Consistent Strings |
Solution |
|
Easy |
String |
1680 |
Concatenation of Consecutive Binary Numbers |
Solution |
|
Medium |
Math |
1679 |
Max Number of K-Sum Pairs |
Solution |
|
Medium |
HashTable |
1678 |
Goal Parser Interpretation |
Solution |
|
Easy |
String |
1675 |
Minimize Deviation in Array |
Solution |
|
Hard |
Heap, Ordered Map |
1673 |
Find the Most Competitive Subsequence |
Solution |
๐บ |
Medium |
Stack, Greedy |
1672 |
Richest Customer Wealth |
Solution |
|
Easy |
Array |
1670 |
Design Front Middle Back Queue |
Solution |
|
Medium |
Linked List, Design, Dequeu |
1669 |
Merge In Between Linked Lists |
Solution |
|
Medium |
LinedList |
1668 |
Maximum Repeating Substring |
Solution |
|
Easy |
String |
1664 |
Ways to Make a Fair Array |
Javascript |
|
Medium |
Greedy |
1663 |
Smallest String With A Given Numeric Value |
Solution |
๐บ |
Medium |
Greedy |
1662 |
Check If Two String Arrays are Equivalent |
Solution |
|
Easy |
String |
1658 |
Minimum Operations to Reduce X to Zero |
Javascript, Java |
|
Medium |
Greedy |
1657 |
Determine if Two Strings Are Close |
Solution |
๐บ |
Medium |
Greedy |
1656 |
Design an Ordered Stream |
Solution |
|
Easy |
Array, Design |
1652 |
Defuse the Bomb |
Solution |
|
Easy |
Array |
1646 |
Get Maximum in Generated Array |
Solution |
|
Easy |
Array |
1641 |
Count Sorted Vowel Strings |
Solution |
๐บ |
Medium |
Math, DP, Backtracking |
1640 |
Check Array Formation Through Concatenation |
Solution |
|
Easy |
Array, Sort |
1637 |
Widest Vertical Area Between Two Points Containing No Points |
Javascript |
|
Medium |
Sort |
1636 |
Sort Array by Increasing Frequency |
Solution |
|
Easy |
Array, Sort |
1630 |
Arithmetic Subarrays |
Solution |
|
Medium |
Sort |
1629 |
Slowest Key |
Solution |
|
Easy |
Array |
1626 |
Best Team With No Conflicts |
Solution |
|
Medium |
DP |
1625 |
Lexicographically Smallest String After Applying Operations |
Solution |
|
Medium |
BFS, DFS |
1624 |
Largest Substring Between Two Equal Characters |
Solution |
๐บ |
Easy |
String |
1620 |
Coordinate With Maximum Network Quality |
Solution |
๐บ |
Medium |
Greedy |
1619 |
Mean of Array After Removing Some Elements |
Solution |
๐บ |
Easy |
Array |
1614 |
Maximum Nesting Depth of the Parentheses |
Solution |
|
Easy |
String |
1609 |
Even Odd Tree |
Solution |
|
Medium |
Tree |
1608 |
Special Array With X Elements Greater Than or Equal X |
Solution |
|
Easy |
Array |
1604 |
Alert Using Same Key-Card Three or More Times in a One Hour Period |
Solution |
|
Medium |
String, Ordered Map |
1603 |
Design Parking System |
Solution |
|
Easy |
Design |
1601 |
Maximum Number of Achievable Transfer Requests |
Solution |
|
Hard |
Backtracking |
1598 |
Crawler Log Folder |
Solution |
|
Easy |
Stack |
1592 |
Rearrange Spaces Between Words |
Solution |
|
Easy |
String |
1588 |
Sum of All Odd Length Subarrays |
Solution |
|
Easy |
Array |
1583 |
Count Unhappy Friends |
Solution |
|
Medium |
Array |
1582 |
Special Positions in a Binary Matrix |
Solution |
|
Easy |
Array |
1577 |
Number of Ways Where Square of Number Is Equal to Product of Two Numbers |
Solution |
|
Medium |
HashTable, Math |
1576 |
Replace All ?'s to Avoid Consecutive Repeating Characters |
Solution |
๐บ |
Easy |
String |
1574 |
Shortest Subarray to be Removed to Make Array Sorted |
Solution |
|
Medium |
Array, Binary Search |
1572 |
Matrix Diagonal Sum |
Solution |
|
Easy |
Array |
1570 |
Dot Product of Two Sparse Vectors |
Solution |
|
Easy |
Array, HashTable, Two Pointers |
1567 |
Maximum Length of Subarray With Positive Product |
Solution |
๐บ |
Medium |
Greedy |
1566 |
Detect Pattern of Length M Repeated K or More Times |
Solution |
๐บ |
Easy |
Array |
1561 |
Maximum Number of Coins You Can Get |
Solution |
๐บ |
Medium |
Sort |
1560 |
Most Visited Sector in a Circular Track |
Solution |
|
Easy |
Array |
1558 |
Minimum Numbers of Function Calls to Make Target Array |
Solution |
|
Medium |
Greedy |
1557 |
Minimum Number of Vertices to Reach All Nodes |
Solution |
๐บ |
Medium |
Graph |
1556 |
Thousand Separator |
Solution |
๐บ |
Easy |
String |
1551 |
Minimum Operations to Make Array Equal |
Solution |
๐บ |
Medium |
Math |
1550 |
Three Consecutive Odds |
Solution |
|
Easy |
Array |
1545 |
Find Kth Bit in Nth Binary String |
Solution |
๐บ |
Medium |
String |
1544 |
Make The String Great |
Solution |
๐บ |
Easy |
String, Stack |
1541 |
Minimum Insertions to Balance a Parentheses String |
Solution |
๐บ |
Medium |
String, Stack |
1539 |
Kth Missing Positive Number |
Solution |
๐บ |
Easy |
Array, HashTable |
1535 |
Find the Winner of an Array Game |
Solution |
๐บ |
Medium |
Array |
1534 |
Count Good Triplets |
Solution |
|
Easy |
Array |
1528 |
Shuffle String |
Solution |
|
Easy |
Sort |
1526 |
Minimum Number of Increments on Subarrays to Form a Target Array |
Solution |
|
Hard |
Segment Tree |
1525 |
Number of Good Ways to Split a String |
Solution |
๐บ |
Medium |
String, Bit Manipulation |
1524 |
Number of Sub-arrays With Odd Sum |
Solution |
|
Medium |
Array, Math |
1523 |
Count Odd Numbers in an Interval Range |
Solution |
๐บ |
Easy |
Math |
1518 |
Water Bottles |
Solution |
|
Easy |
Greedy |
1514 |
Path with Maximum Probability |
Solution |
|
Medium |
Graph |
1512 |
Number of Good Pairs |
Solution |
|
Easy |
Array, HashTable, Math |
1508 |
Range Sum of Sorted Subarray Sums |
Solution |
|
Medium |
Array, Sort |
1507 |
Reformat Date |
Solution |
|
Easy |
String |
1502 |
Can Make Arithmetic Progression From Sequence |
Solution |
|
Easy |
Array, Sort |
1496 |
Path Crossing |
Solution |
|
Easy |
String |
1493 |
Longest Subarray of 1's After Deleting One Element |
Solution |
๐บ |
Medium |
Array |
1492 |
The kth Factor of n |
Solution |
|
Medium |
Math |
1491 |
Average Salary Excluding the Minimum and Maximum Salary |
Solution |
|
Easy |
Array, Sort |
1490 |
Clone N-ary Tree |
Solution |
๐บ |
Medium |
HashTable, Tree, DFS, BFS |
1487 |
Making File Names Unique |
Solution |
|
Medium |
HashTable, String |
1486 |
XOR Operation in an Array |
Solution |
|
Medium |
Array, Bit Manipulation |
1485 |
Clone Binary Tree With Random Pointer |
Solution |
|
Medium |
HashTable, Tree, DFS, BFS |
1481 |
Least Number of Unique Integers after K Removals |
Solution |
|
Medium |
Array, Sort |
1480 |
Running Sum of 1d Array |
Solution, C++ |
|
Easy |
Array |
1476 |
Subrectangle Queries |
Solution |
|
Medium |
Array |
1475 |
Final Prices With a Special Discount in a Shop |
Solution |
|
Easy |
Array |
1474 |
Delete N Nodes After M Nodes of a Linked List |
Solution |
|
Easy |
LinkedList |
1471 |
The k Strongest Values in an Array |
Solution |
|
Medium |
Array, Sort |
1470 |
Shuffle the Array |
Solution, C++ |
|
Easy |
Array |
1469 |
Find All The Lonely Nodes |
Solution |
|
Easy |
Tree, DFS |
1466 |
Reorder Routes to Make All Paths Lead to the City Zero |
Solution |
|
Medium |
Tree, DFS |
1464 |
Maximum Product of Two Elements in an Array |
Solution |
|
Easy |
Array |
1461 |
Check If a String Contains All Binary Codes of Size K |
Solution |
|
Medium |
String, Bit Manipulation |
1460 |
Make Two Arrays Equal by Reversing Sub-arrays |
Solution |
|
Easy |
Array |
1457 |
Pseudo-Palindromic Paths in a Binary Tree |
Solution |
|
Medium |
Bit Manipulation, Tree, DFS |
1456 |
Maximum Number of Vowels in a Substring of Given Length |
Solution |
|
Medium |
String, Sliding Window |
1455 |
Check If a Word Occurs As a Prefix of Any Word in a Sentence |
Solution |
|
Easy |
String |
1452 |
People Whose List of Favorite Companies Is Not a Subset of Another List |
Solution |
|
Medium |
String, Sort |
1451 |
Rearrange Words in a Sentence |
Solution |
|
Medium |
String, Sort |
1450 |
Number of Students Doing Homework at a Given Time |
Solution |
|
Easy |
Array |
1448 |
Count Good Nodes in Binary Tree |
Solution |
|
Medium |
Tree, DFS |
1447 |
Simplified Fractions |
Solution |
|
Medium |
Math |
1446 |
Consecutive Characters |
Solution |
|
Easy |
String |
1441 |
Build an Array With Stack Operations |
Solution |
|
Easy |
Stack |
1437 |
Check If All 1's Are at Least Length K Places Away |
Solution |
|
Medium |
Array |
1436 |
Destination City |
Solution |
|
Easy |
String |
1432 |
Max Difference You Can Get From Changing an Integer |
Solution |
|
Medium |
String |
1431 |
Kids With the Greatest Number of Candies |
Solution, C++ |
|
Easy |
Array |
1428 |
Leftmost Column with at Least a One |
Solution |
|
Medium |
Array |
1427 |
Perform String Shifts |
Solution |
|
Easy |
Array, Math |
1426 |
Counting Elements |
Solution |
|
Easy |
Array |
1423 |
Maximum Points You Can Obtain from Cards |
Solution |
|
Medium |
Array, DP, Sliding Window |
1422 |
Maximum Score After Splitting a String |
Solution |
|
Easy |
String |
1418 |
Display Table of Food Orders in a Restaurant |
Solution |
|
Medium |
HashTable |
1417 |
Reformat The String |
Solution |
|
Easy |
String |
1415 |
The k-th Lexicographical String of All Happy Strings of Length n |
Solution |
|
Medium |
Backtracking |
1413 |
Minimum Value to Get Positive Step by Step Sum |
Solution |
|
Easy |
Array |
1410 |
HTML Entity Parser |
Solution |
|
Medium |
String, Stack |
1409 |
Queries on a Permutation With Key |
Solution |
|
Medium |
Array |
1408 |
String Matching in an Array |
Solution |
|
Easy |
String |
1403 |
Minimum Subsequence in Non-Increasing Order |
Solution |
|
Easy |
Greedy, Sort |
1402 |
Reducing Dishes |
Solution |
|
Hard |
Dynamic Programming |
1401 |
Circle and Rectangle Overlapping |
Solution |
|
Medium |
Geometry |
1400 |
Construct K Palindrome Strings |
Solution |
|
Medium |
Greedy |
1399 |
Count Largest Group |
Solution |
|
Easy |
Array |
1396 |
Design Underground System |
Solution |
|
Medium |
Design |
1395 |
Count Number of Teams |
Solution |
|
Medium |
Array |
1394 |
Find Lucky Integer in an Array |
Solution |
|
Easy |
Array |
1392 |
Longest Happy Prefix |
Solution |
|
Hard |
String, Rolling Hash |
1390 |
Four Divisors |
Solution |
|
Medium |
Math |
1389 |
Create Target Array in the Given Order |
Solution |
|
Easy |
Array |
1388 |
Pizza With 3n Slices |
Solution |
|
Hard |
DP |
1387 |
Sort Integers by The Power Value |
Solution |
|
Medium |
Sort, Graph |
1386 |
Cinema Seat Allocation |
Solution |
|
Medium |
Array, Greedy |
1385 |
Find the Distance Value Between Two Arrays |
Solution |
|
Easy |
Array |
1382 |
Balance a Binary Search Tree |
Solution |
|
Medium |
Binary Search Tree |
1381 |
Design a Stack With Increment Operation |
Solution |
|
Medium |
Stack, Design |
1380 |
Lucky Numbers in a Matrix |
Solution |
|
Easy |
Array |
1379 |
Find a Corresponding Node of a Binary Tree in a Clone of That Tree |
Solution |
|
Medium |
Tree |
1377 |
Frog Position After T Seconds |
Solution |
|
Hard |
DFS, BFS |
1376 |
Time Needed to Inform All Employees |
Solution |
|
Medium |
DFS |
1375 |
Bulb Switcher III |
Solution |
|
Medium |
Array |
1374 |
Generate a String With Characters That Have Odd Counts |
Solution |
|
Easy |
String |
1373 |
Maximum Sum BST in Binary Tree |
Solution |
|
Hard |
DP, BST |
1372 |
Longest ZigZag Path in a Binary Tree |
Solution |
|
Hard |
DP, Tree |
1371 |
Find the Longest Substring Containing Vowels in Even Counts |
Solution |
|
Medium |
String |
1370 |
Increasing Decreasing String |
Solution |
|
Easy |
String, Sort |
1367 |
Linked List in Binary Tree |
Solution |
|
Medium |
DP, Linked List, Tree |
1366 |
Rank Teams by Votes |
Solution |
|
Medium |
Array, Sort |
1365 |
How Many Numbers Are Smaller Than the Current Number |
Solution |
|
Easy |
Array, HashTable |
1362 |
Closest Divisors |
Solution |
|
Medium |
Math |
1361 |
Validate Binary Tree Nodes |
Solution |
|
Medium |
Graph |
1360 |
Number of Days Between Two Dates |
Solution |
|
Easy |
|
1358 |
Number of Substrings Containing All Three Characters |
Solution |
|
Medium |
String |
1357 |
Apply Discount Every n Orders |
Solution |
|
Medium |
Design |
1356 |
Sort Integers by The Number of 1 Bits |
Solution |
|
Easy |
Sort, Bit Manipulation |
1354 |
Construct Target Array With Multiple Sums |
Solution |
|
Hard |
Greedy |
1353 |
Maximum Number of Events That Can Be Attended |
Solution |
|
Medium |
Greedy, Sort, Segment Tree |
1352 |
Product of the Last K Numbers |
Solution |
|
Medium |
Array, Design |
1351 |
Count Negative Numbers in a Sorted Matrix |
Solution |
|
Easy |
Array, Binary Search |
1349 |
Maximum Students Taking Exam |
Solution |
|
Hard |
Dynamic Programming |
1348 |
Tweet Counts Per Frequency |
Solution |
|
Medium |
Design |
1347 |
Minimum Number of Steps to Make Two Strings Anagram |
Solution |
|
Easy |
String |
1346 |
Check If N and Its Double Exist |
Solution |
|
Easy |
Array |
1345 |
Jump Game IV |
Solution |
|
Hard |
BFS |
1344 |
Angle Between Hands of a Clock |
Solution |
|
Medium |
Math |
1343 |
Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold |
Solution |
|
Medium |
Array |
1342 |
Number of Steps to Reduce a Number to Zero |
Solution |
|
Easy |
Bit Manipulation |
1341 |
The K Weakest Rows in a Matrix |
Solution |
|
Easy |
|
1339 |
Maximum Product of Splitted Binary Tree |
Solution |
|
Medium |
DP, Tree |
1338 |
Reduce Array Size to The Half |
Solution |
|
Medium |
|
1337 |
Remove Palindromic Subsequences |
Solution |
|
Easy |
String |
1333 |
Filter Restaurants by Vegan-Friendly, Price and Distance |
Solution |
|
Medium |
|
1332 |
Remove Palindromic Subsequences |
Solution |
|
Easy |
String |
1331 |
Rank Transform of an Array |
Solution |
|
Easy |
|
1329 |
Sort the Matrix Diagonally |
Solution |
|
Medium |
|
1325 |
Delete Leaves With a Given Value |
Solution |
|
Medium |
Tree |
1324 |
Print Words Vertically |
Solution |
|
Medium |
String |
1323 |
Maximum 69 Number |
Solution |
|
Easy |
Math |
1317 |
Convert Integer to the Sum of Two No-Zero Integers |
Solution |
|
Easy |
|
1315 |
Sum of Nodes with Even-Valued Grandparent |
Solution |
|
Medium |
Tree, DFS |
1314 |
Matrix Block Sum |
Solution |
|
Medium |
Dynamic Programming |
1313 |
Decompress Run-Length Encoded List |
Solution |
|
Easy |
Array |
1305 |
All Elements in Two Binary Search Trees |
Solution |
|
Medium |
|
1304 |
Find N Unique Integers Sum up to Zero |
Solution |
|
Easy |
|
1302 |
Deepest Leaves Sum |
Solution |
|
Medium |
|
1300 |
Sum of Mutated Array Closest to Target |
Solution |
|
Medium |
|
1299 |
Replace Elements with Greatest Element on Right Side |
Solution |
|
Easy |
|
1297 |
Maximum Number of Occurrences of a Substring |
Solution |
|
Medium |
|
1296 |
Divide Array in Sets of K Consecutive Numbers |
Solution |
|
Medium |
|
1295 |
Find Numbers with Even Number of Digits |
Java Javascript |
๐บ |
Easy |
|
1291 |
Sequential Digits |
Solution |
|
Medium |
|
1290 |
Convert Binary Number in a Linked List to Integer |
Solution |
|
Easy |
|
1289 |
Minimum Falling Path Sum II |
Solution |
|
Hard |
Dynamic Programming |
1287 |
Element Appearing More Than 25% In Sorted Array |
Solution |
๐บ |
Easy |
|
1286 |
Iterator for Combination |
Solution |
|
Medium |
Backtracking, Design |
1283 |
Find the Smallest Divisor Given a Threshold |
Solution |
Medium |
|
|
1282 |
Group the People Given the Group Size They Belong To |
Solution |
๐บ |
Medium |
|
1281 |
Subtract the Product and Sum of Digits of an Integer |
Solution |
|
Easy |
|
1277 |
Count Square Submatrices with All Ones |
Solution |
|
Medium |
|
1275 |
Find Winner on a Tic Tac Toe Game |
Solution |
|
Easy |
Array |
1273 |
Delete Tree Nodes |
Solution |
|
Medium |
Dynamic Programming, DFS |
1271 |
Hexspeak |
Solution |
|
Easy |
|
1268 |
Search Suggestions System |
Solution |
๐บ |
Medium |
String |
1267 |
Count Servers that Communicate |
Solution |
|
Medium |
|
1266 |
Minimum Time Visiting All Points |
Solution |
|
Easy |
|
1265 |
Print Immutable Linked List in Reverse |
Solution |
|
Medium |
|
1261 |
Find Elements in a Contaminated Binary Tree |
Solution |
|
Medium |
Tree, HashTable |
1260 |
Shift 2D Grid |
Solution |
๐บ |
Easy |
|
1258 |
Synonymous Sentences |
Solution |
|
Medium |
Backtracking |
1252 |
Cells with Odd Values in a Matrix |
Solution |
|
Easy |
|
1249 |
Minimum Remove to Make Valid Parentheses |
Solution |
|
Medium |
String, Stack |
1243 |
Array Transformation |
Solution |
๐บ |
Easy |
|
1237 |
Find Positive Integer Solution for a Given Equation |
Solution |
|
Easy |
|
1232 |
Check If It Is a Straight Line |
Solution |
๐บ |
Easy |
|
1228 |
Missing Number In Arithmetic Progression |
Solution |
|
Easy |
|
1221 |
Split a String in Balanced Strings |
Solution |
|
Easy |
Greedy |
1219 |
Path with Maximum Gold |
Solution |
|
Medium |
Backtracking |
1217 |
Play with Chips |
Solution |
|
Easy |
Array, Math, Greedy |
1214 |
Two Sum BSTs |
Solution |
|
Medium |
Binary Search Tree |
1213 |
Intersection of Three Sorted Arrays |
Solution |
๐บ |
Easy |
|
1209 |
Remove All Adjacent Duplicates in String II |
Solution |
|
Medium |
Stack |
1207 |
Unique Number of Occurrences |
Solution |
๐บ |
Easy |
|
1200 |
Minimum Absolute Difference |
Solution |
๐บ |
Easy |
|
1198 |
Find Smallest Common Element in All Rows |
Solution |
๐บ |
Easy |
|
1196 |
How Many Apples Can You Put into the Basket |
Solution |
๐บ |
Easy |
|
1190 |
Reverse Substrings Between Each Pair of Parentheses |
Solution |
|
Medium |
Stack |
1189 |
Maximum Number of Balloons |
Solution |
๐บ |
Easy |
|
1185 |
Day of the Week |
Solution |
|
Easy |
|
1184 |
Distance Between Bus Stops |
Solution |
๐บ |
Easy |
|
1182 |
Shortest Distance to Target Color |
Solution |
|
Medium |
Binary Search |
1180 |
Count Substrings with Only One Distinct Letter |
Solution |
|
Easy |
Math, String |
1176 |
Diet Plan Performance |
Solution |
|
Easy |
Array, Sliding Window |
1175 |
Prime Arrangements |
Solution |
|
Easy |
Math |
1171 |
Remove Zero Sum Consecutive Nodes from Linked List |
Solution |
|
Medium |
LinkedList |
1165 |
Single-Row Keyboard |
Solution |
|
Easy |
|
1161 |
Maximum Level Sum of a Binary Tree |
Solution |
|
Medium |
Graph |
1160 |
Find Words That Can Be Formed by Characters |
Solution |
|
Easy |
|
1154 |
Day of the Year |
Solution |
|
Easy |
|
1152 |
Analyze User Website Visit Pattern |
Solution |
๐บ |
Medium |
HashTable, Sort, Array |
1150 |
Check If a Number Is Majority Element in a Sorted Array |
Solution |
๐บ |
Easy |
|
1146 |
Snapshot Array |
Javascript |
|
Easy |
|
1138 |
Alphabet Board Path |
Solution |
๐บ |
Medium |
HashTable, String |
1137 |
N-th Tribonacci Number |
Solution |
|
Easy |
|
1136 |
Parallel Courses |
Solution |
|
Medium |
|
1134 |
Armstrong Number |
Solution |
๐บ |
Easy |
|
1133 |
Largest Unique Number |
Solution |
๐บ |
Easy |
|
1128 |
Number of Equivalent Domino Pairs |
Solution |
๐บ |
Easy |
|
1122 |
Relative Sort Array |
Solution |
|
Easy |
|
1170 |
Compare Strings by Frequency of the Smallest Character |
Solution |
|
Easy |
|
1119 |
Remove Vowels from a String |
Solution |
๐บ |
Easy |
|
1118 |
Number of Days in a Month |
Solution |
|
Easy |
|
1114 |
Print in Order |
Solution |
|
Easy |
|
1110 |
Delete Nodes And Return Forest |
Solution |
|
Medium |
Tree, DFS |
1108 |
Defanging an IP Address |
Solution |
๐บ |
Easy |
|
1104 |
Path In Zigzag Labelled Binary Tree |
Solution |
|
Medium |
Math, Tree |
1103 |
Distribute Candies to People |
Solution |
|
Easy |
Math |
1100 |
Find K-Length Substrings With No Repeated Characters |
Solution |
|
Medium |
String, Sliding Window |
1099 |
Two Sum Less Than K |
Solution |
๐บ |
Easy |
|
1090 |
Largest Values From Labels |
Solution |
๐บ |
Medium |
HashTable, Greedy |
1091 |
Shortest Path in Binary Matrix |
Solution |
|
Medium |
BFS |
1089 |
Duplicate Zeros |
Solution |
|
Easy |
|
1087 |
Brace Expansion |
Solution |
|
Medium |
Backtracking |
1086 |
High Five |
Solution |
๐บ |
Easy |
|
1085 |
Sum of Digits in the Minimum Number |
Solution |
๐บ |
Easy |
|
1079 |
Letter Tile Possibilities |
Solution |
|
Medium |
|
1078 |
Occurrences After Bigram |
Solution |
|
Easy |
|
1071 |
Greatest Common Divisor of Strings |
Solution |
|
Easy |
|
1066 |
Campus Bikes II |
Solution |
|
Medium |
Backtracking, DP |
1065 |
Index Pairs of a String |
Solution |
|
Medium |
|
1062 |
Longest Repeating Substring |
Solution |
|
Medium |
|
1057 |
Campus Bikes |
Solution |
|
Medium |
|
1056 |
Confusing Number |
Solution |
|
Easy |
|
1055 |
Fixed Point |
Solution |
|
Easy |
|
1051 |
Height Checker |
Solution |
|
Easy |
|
1047 |
Remove All Adjacent Duplicates In String |
Solution |
|
Easy |
|
1046 |
Last Stone Weight |
Solution |
๐บ |
Easy |
|
1043 |
Partition Array for Maximum Sum |
Solution |
|
Medium |
DP |
1038 |
Binary Search Tree to Greater Sum Tree |
Solution |
|
Medium |
DFS, tree |
1037 |
Valid Boomerang |
Solution |
|
Easy |
Math |
1033 |
Moving Stones Until Consecutive |
Solution |
|
Easy |
Math |
1030 |
Matrix Cells in Distance Order |
Solution |
|
Easy |
|
1029 |
Two City Scheduling |
Solution |
|
Easy |
|
1025 |
Divisor Game |
Solution |
|
Easy |
|
1022 |
Sum of Root To Leaf Binary Numbers |
Solution |
|
Easy |
|
1021 |
Remove Outermost Parentheses |
Solution |
|
Easy |
|
1020 |
Number of Enclaves |
Solution |
|
Medium |
Graph, DFS, BFS, recursion |
1019 |
Next Greater Node In Linked List |
Solution |
|
Medium |
Linked List, Stack |
1018 |
Binary Prefix Divisible By 5 |
Solution |
|
Easy |
|
1014 |
Best Sightseeing Pair |
Solution |
|
Medium |
|
1013 |
Partition Array Into Three Parts With Equal Sum |
Solution |
|
Easy |
|
1011 |
Capacity To Ship Packages Within D Days |
Solution |
|
Medium |
Binary Search |
1010 |
Pairs of Songs With Total Durations Divisible by 60 |
Solution |
|
Easy |
|
1009 |
Complement of Base 10 Integer |
Solution |
|
Easy |
|
1008 |
Construct Binary Search Tree from Preorder Traversal |
Solution |
|
Medium |
Recursion |
1005 |
Maximize Sum Of Array After K Negations |
Solution |
๐บ |
Easy |
|
1004 |
Max Consecutive Ones III |
Solution |
๐บ |
Medium |
Two Pointers, Sliding Window |
1003 |
Check If Word Is Valid After Substitutions |
Solution |
|
Medium |
|
1002 |
Find Common Characters |
Solution |
|
Easy |
|
999 |
Available Captures for Rook |
Solution |
|
Easy |
|
991 |
Broken Calculator |
Solution |
|
Medium |
Math, Greedy |
981 |
Time Based Key-Value Store |
Solution |
๐บ |
Medium |
|
997 |
Find the Town Judge |
Solution |
|
Easy |
|
994 |
Rotting Oranges |
Solution |
|
Easy |
BFS |
993 |
Cousins in Binary Tree |
Solution |
|
Easy |
Tree, BFS |
989 |
Add to Array-Form of Integer |
Solution |
|
Easy |
Array |
988 |
Smallest String Starting From Leaf |
Solution |
|
Medium |
Tree, DFS |
987 |
Vertical Order Traversal of a Binary Tree |
Solution |
|
Medium |
Recursion |
986 |
Interval List Intersections |
Solution |
|
Medium |
Two Pointers |
985 |
Sum of Even Numbers After Queries |
Solution |
|
Easy |
Array |
980 |
Unique Paths III |
Solution |
|
Hard |
Backtracking, DFS |
979 |
Distribute Coins in Binary Tree |
Solution |
|
Medium |
Recursion |
977 |
Squares of a Sorted Array |
Solution |
|
Easy |
Array |
976 |
Largest Perimeter Triangle |
Solution |
|
Easy |
Math Array |
974 |
Subarray Sums Divisible by K |
Solution |
|
Medium |
Array |
973 |
K Closest Points to Origin |
Solution |
|
Easy |
Math Sort |
970 |
Powerful Integers |
Solution |
|
Easy |
Math |
966 |
Vowel Spellchecker |
Solution |
|
Medium |
Hash Table, String |
965 |
Univalued Binary Tree |
Solution |
|
Easy |
DFS, recursion |
961 |
N-Repeated Element in Size 2N Array |
Solution |
|
Easy |
|
958 |
Check Completeness of a Binary Tree |
Solution |
|
Medium |
Tree |
957 |
Prison Cells After N Days |
Solution |
๐บ |
Medium |
|
954 |
Array of Doubled Pairs |
Solution |
๐บ |
Medium |
|
953 |
Verifying an Alien Dictionary |
Solution |
|
Easy |
|
951 |
Flip Equivalent Binary Trees |
Solution |
|
Medium |
Tree, DFS, recursion |
950 |
Reveal Cards In Increasing Order |
Solution |
|
Medium |
|
946 |
Validate Stack Sequences |
Solution |
|
Medium |
Stack |
944 |
Delete Columns to Make Sorted |
Solution |
|
Easy |
|
942 |
DI String Match |
Solution |
|
Easy |
|
941 |
Valid Mountain Array |
Solution |
|
Easy |
|
938 |
Range Sum of BST |
Solution |
|
Medium |
BST, recursion, DFS |
937 |
Reorder Log Files |
Solution |
|
Easy |
|
936 |
Stamping The Sequence |
Solution |
|
Hard |
String, Greedy |
935 |
Knight Dialer |
Solution |
|
Medium |
|
933 |
Number of Recent Calls |
Solution |
|
Easy |
|
931 |
Minimum Falling Path Sum |
Solution |
|
Medium |
Dynamic Programming |
929 |
Unique Email Addresses |
Solution |
|
Easy |
|
925 |
Long Pressed Name |
Solution |
|
Easy |
|
923 |
3Sum With Multiplicity |
Solution |
|
Medium |
Two Pointers |
922 |
Sort Array By Parity II |
Solution |
|
Easy |
|
921 |
Minimum Add to Make Parentheses Valid |
Solution |
|
Medium |
Stack, Greedy |
917 |
Reverse Only Letters |
Solution |
|
Easy |
|
914 |
X of a Kind in a Deck of Cards |
Solution |
|
Easy |
|
912 |
Sort an Array |
Solution |
|
Easy |
|
908 |
Smallest Range I |
Solution |
|
Easy |
|
901 |
Online Stock Span |
Solution |
|
Medium |
Stack |
904 |
Fruit Into Baskets |
Solution |
๐บ |
Medium |
Two Pointers |
900 |
RLE Iterator |
Solution |
|
Medium |
|
897 |
Increasing Order Search Tree |
Solution |
|
Easy |
DFS, recursion |
896 |
Monotonic Array |
Solution |
|
Easy |
|
895 |
Maximum Frequency Stack |
Solution |
HashTable, Stack |
Hard |
|
890 |
Find and Replace Pattern |
Solution |
|
Medium |
|
893 |
Groups of Special-Equivalent Strings |
Solution |
๐บ |
Easy |
|
888 |
Fair Candy Swap |
Solution |
|
Easy |
|
885 |
Spiral Matrix III |
Solution |
๐บ |
Medium |
|
884 |
Uncommon Words from Two Sentences |
Solution |
|
Easy |
|
883 |
Projection Area of 3D Shapes |
Solution |
|
Easy |
Math |
881 |
Boats to Save People |
Solution |
|
Medium |
Two Pointers, Greedy |
880 |
Decoded String at Index |
Solution |
|
Medium |
Stack |
877 |
Stone Game |
Solution |
|
Medium |
Math, DP, Minimax |
876 |
Middle of the Linked List |
Solution |
|
Easy |
|
872 |
Leaf-Similar Trees |
Solution |
|
Easy |
DFS, recursion |
870 |
Advantage Shuffle |
Solution |
|
Medium |
Array, Greedy |
868 |
Binary Gap |
Solution |
|
Easy |
|
867 |
Transpose Matrix |
Solution |
|
Easy |
|
861 |
Score After Flipping Matrix |
Solution |
|
Medium |
Greedy |
860 |
Lemonade Change |
Solution |
|
Easy |
|
859 |
Buddy Strings |
Solution |
|
Easy |
|
856 |
Score of Parentheses |
Solution |
|
Medium |
Stack, String |
852 |
Peak Index in a Mountain Array |
Solution |
|
Easy |
|
849 |
Maximize Distance to Closest Person |
Solution |
|
Easy |
|
844 |
Backspace String Compare |
Solution |
|
Easy |
|
841 |
Keys and Rooms |
Solution |
|
Easy |
DFS, Graph |
840 |
Magic Squares In Grid |
Solution |
|
Easy |
|
838 |
Push Dominoes |
Solution |
๐บ |
Medium |
Two Pointers, DP |
836 |
Rectangle Overlap |
Solution |
๐บ |
Easy |
|
832 |
Flipping an Image |
Solution |
|
Easy |
|
830 |
Positions of Large Groups |
Solution |
|
Easy |
|
824 |
Goat Latin |
Solution |
|
Easy |
|
823 |
Binary Trees With Factors |
Solution |
|
Medium |
|
821 |
Shortest Distance to a Character |
Solution |
|
Easy |
|
820 |
Short Encoding of Words |
Solution |
|
Medium |
|
819 |
Most Common Word |
Solution |
|
Easy |
HashMap |
814 |
Binary Tree Pruning |
Solution |
|
Medium |
recursion, DFS |
811 |
Subdomain Visit Count |
Solution |
|
Easy |
HashMap |
809 |
Expressive Words |
Solution |
|
Medium |
|
807 |
Max Increase to Keep City Skyline |
Solution |
|
Medium |
|
806 |
Number of Lines To Write String |
Solution |
|
Easy |
|
804 |
Unique Morse Code Words |
Solution |
|
Easy |
|
800 |
Similar RGB Color |
Solution |
|
Easy |
|
799 |
Champagne Tower |
Solution |
|
Medium |
|
796 |
Rotate String |
Solution |
|
Easy |
|
791 |
Custom Sort String |
Solution |
|
Medium |
|
789 |
Escape The Ghosts |
Solution |
|
Medium |
Math |
788 |
Rotated Digits |
Solution |
|
Easy |
|
784 |
Letter Case Permutation |
Solution |
|
Easy |
|
783 |
Minimum Distance Between BST Nodes |
Solution |
|
Easy |
|
781 |
Rabbits in Forest |
Solution |
๐บ |
Medium |
HashTable, Math |
779 |
K-th Symbol in Grammar |
Solution |
|
Medium |
|
776 |
Split BST |
Solution |
|
Medium |
Recursion |
775 |
Global and Local Inversions |
Solution |
|
Medium |
Array, Math |
771 |
Jewels and Stones |
Solution |
|
Easy |
|
769 |
Max Chunks To Make Sorted |
Solution |
|
Medium |
Array |
767 |
Reorganize String |
Solution |
|
Medium |
|
766 |
Toeplitz Matrix |
Solution |
|
Easy |
|
765 |
Couples Holding Hands |
Solution |
|
Hard |
|
764 |
Largest Plus Sign |
Solution |
|
Medium |
DP |
763 |
Partition Labels |
Solution |
|
Medium |
|
762 |
Prime Number of Set Bits in Binary Representation |
Solution |
|
Easy |
|
760 |
Find Anagram Mappings |
Solution |
|
Easy |
|
758 |
Bold Words in String |
Solution |
|
Easy |
|
757 |
Set Intersection Size At Least Two |
Solution |
|
Hard |
|
756 |
Pyramid Transition Matrix |
Solution |
|
Medium |
Backtracking |
755 |
Pour Water |
Solution |
|
Medium |
Array |
754 |
Reach a Number |
Solution |
|
Medium |
Math |
750 |
Number Of Corner Rectangles |
Solution |
|
Medium |
|
748 |
Shortest Completing Word |
Solution |
|
Easy |
|
747 |
Largest Number Greater Than Twice of Others |
Solution |
|
Easy |
|
746 |
Min Cost Climbing Stairs |
Solution |
|
Easy |
|
744 |
Find Smallest Letter Greater Than Target |
Solution |
|
Easy |
|
743 |
Network Delay Time |
Solution |
|
Medium |
Graph, Djikstra |
742 |
Closest Leaf in a Binary Tree |
Solution |
|
Medium |
Tree |
740 |
Delete and Earn |
Solution |
|
Medium |
|
739 |
Daily Temperatures |
Solution |
|
Medium |
|
738 |
Monotone Increasing Digits |
Solution |
|
Medium |
|
737 |
Sentence Similarity II |
Solution |
|
Medium |
Union Find |
735 |
Asteroid Collision |
Solution |
|
Medium |
Stack |
734 |
Sentence Similarity |
Solution |
|
Easy |
HashTable |
733 |
Flood Fill |
Solution |
|
Easy |
BFS, DFS |
729 |
My Calendar I |
Solution |
|
Medium |
|
728 |
Self Dividing Numbers |
Solution |
|
Easy |
|
727 |
Minimum Window Subsequence |
Solution |
|
Hard |
DP |
725 |
Split Linked List in Parts |
Solution |
|
Medium |
LinkedList |
724 |
Find Pivot Index |
Solution |
|
Easy |
Array |
723 |
Candy Crush |
Solution |
|
Medium |
Array, Two Pointers |
721 |
Accounts Merge |
Solution |
|
Medium |
DFS, Union Find |
720 |
Longest Word in Dictionary |
Solution |
|
Easy |
Trie |
719 |
Find K-th Smallest Pair Distance |
Solution |
|
Hard |
Binary Search |
718 |
Maximum Length of Repeated Subarray |
Solution |
|
Medium |
DP |
717 |
1-bit and 2-bit Characters |
Solution |
|
Easy |
|
716 |
Max Stack |
Solution |
|
Hard |
Design |
714 |
Best Time to Buy and Sell Stock with Transaction Fee |
Solution |
|
Medium |
DP |
713 |
Subarray Product Less Than K |
Solution |
|
Medium |
|
712 |
Minimum ASCII Delete Sum for Two Strings |
Solution |
|
Medium |
DP |
709 |
To Lower Case |
Solution |
|
Easy |
String |
706 |
Design HashMap |
Solution |
|
Easy |
Design |
705 |
Design HashSet |
Solution |
|
Easy |
Design |
704 |
Binary Search |
Solution |
|
Easy |
Binary Search |
703 |
Kth Largest Element in a Stream |
Solution |
|
Easy |
|
701 |
Insert into a Binary Search Tree |
Solution |
|
Medium |
DFS, recursion |
700 |
Search in a Binary Search Tree |
Solution |
|
Easy |
recusion, dfs |
699 |
Falling Squares |
Solution |
|
Hard |
Segment Tree |
698 |
Partition to K Equal Sum Subsets |
Java, C++ |
|
Medium |
Backtracking + DP |
697 |
Degree of an Array |
Solution |
|
Easy |
|
696 |
Count Binary Substrings |
Solution |
|
Easy |
|
695 |
Max Area of Island |
Solution |
|
Easy |
DFS |
694 |
Number of Distinct Islands |
Solution |
|
Medium |
DFS |
693 |
Binary Number with Alternating Bits |
Solution |
|
Easy |
|
692 |
Top K Frequent Words |
Solution |
|
Medium |
|
691 |
Stickers to Spell Word |
Solution |
|
Hard |
DP |
690 |
Employee Importance |
Solution |
|
Easy |
DFS |
689 |
Maximum Sum of 3 Non-Overlapping Subarrays |
Solution |
|
Hard |
DP |
688 |
Knight Probability in Chessboard |
Solution |
|
Medium |
DP |
687 |
Longest Univalue Path |
Solution |
|
Easy |
DFS |
686 |
Repeated String Match |
Solution |
|
Easy |
|
685 |
Redundant Connection II |
Solution |
|
Hard |
Union Find |
684 |
Redundant Connection |
Solution |
|
Medium |
Union Find |
683 |
K Empty Slots |
Solution |
|
Hard |
|
682 |
Baseball Game |
Solution |
|
Easy |
|
681 |
Next Closest Time |
Solution |
|
Medium |
|
680 |
Valid Palindrome II |
Solution |
|
Easy |
String |
679 |
24 Game |
Solution |
|
Hard |
Recursion |
678 |
Valid Parenthesis String |
Solution |
|
Medium |
Recursion, Greedy |
677 |
Map Sum Pairs |
Solution |
|
Medium |
HashMap, Trie |
676 |
Implement Magic Dictionary |
Solution |
|
Medium |
|
675 |
Cut Off Trees for Golf Event |
Solution |
|
Hard |
BFS |
674 |
Longest Continuous Increasing Subsequence |
Solution |
|
Easy |
|
673 |
Number of Longest Increasing Subsequence |
Solution |
|
Medium |
DP |
672 |
Bulb Switcher II |
Solution |
|
Medium |
Math |
671 |
Second Minimum Node In a Binary Tree |
Solution |
|
Easy |
Tree, DFS |
670 |
Maximum Swap |
Solution |
|
Medium |
String |
669 |
Trim a Binary Search Tree |
Solution |
|
Easy |
Tree, DFS |
668 |
Kth Smallest Number in Multiplication Table |
Solution |
|
Hard |
Binary Search |
667 |
Beautiful Arrangement II |
Solution |
|
Medium |
Array |
666 |
Path Sum IV |
Solution |
|
Medium |
Tree, DFS |
665 |
Non-decreasing Array |
Solution |
|
Easy |
|
664 |
Strange Printer |
Solution |
|
Hard |
DP |
663 |
Equal Tree Partition |
Solution |
|
Medium |
Tree |
662 |
Maximum Width of Binary Tree |
Solution |
|
Medium |
BFS, DFS |
661 |
Image Smoother |
Solution |
|
Easy |
Array |
660 |
Remove 9 |
Solution |
|
Hard |
Math |
659 |
Split Array into Consecutive Subsequences |
Solution |
|
Medium |
HashMap |
658 |
Find K Closest Elements |
Solution |
|
Medium |
|
657 |
Judge Route Circle |
Solution |
|
Easy |
|
656 |
Coin Path |
Solution |
|
Hard |
DP |
655 |
Print Binary Tree |
Solution |
|
Medium |
Recursion |
654 |
Maximum Binary Tree |
Solution |
|
Medium |
Tree |
653 |
Two Sum IV - Input is a BST |
Solution |
|
Easy |
Tree |
652 |
Find Duplicate Subtrees |
Solution |
|
Medium |
Tree |
651 |
4 Keys Keyboard |
Solution |
|
Medium |
DP |
650 |
2 Keys Keyboard |
Solution |
|
Medium |
DP |
649 |
Dota2 Senate |
Solution |
|
Medium |
Greedy |
648 |
Replace Words |
Solution |
|
Medium |
Trie |
647 |
Palindromic Substrings |
Solution |
|
Medium |
DP |
646 |
Maximum Length of Pair Chain |
Solution |
|
Medium |
DP, Greedy |
645 |
Set Mismatch |
Solution |
|
Easy |
|
644 |
Maximum Average Subarray II |
Solution |
|
Hard |
Binary Search |
643 |
Maximum Average Subarray I |
Solution |
|
Easy |
|
642 |
Design Search Autocomplete System |
Solution |
|
Hard |
Design |
640 |
Solve the Equation |
Solution |
|
Medium |
|
639 |
Decode Ways II |
Solution |
|
Hard |
DP |
638 |
Shopping Offers |
Solution |
|
Medium |
DP, DFS |
637 |
Average of Levels in Binary Tree |
Solution |
|
Easy |
|
636 |
Exclusive Time of Functions |
Solution |
|
Medium |
Stack |
635 |
Design Log Storage System |
Solution |
|
Medium |
Design |
634 |
Find the Derangement of An Array |
Solution |
|
Medium |
Math |
633 |
Sum of Square Numbers |
Solution |
|
Easy |
Binary Search |
632 |
Smallest Range |
Solution |
|
Hard |
Heap |
631 |
Design Excel Sum Formula |
Solution |
|
Hard |
Design, Topological Sort |
630 |
Course Schedule III |
Solution |
|
Hard |
Heap, Greedy |
629 |
K Inverse Pairs Array |
Solution |
|
Hard |
DP |
628 |
Maximum Product of Three Numbers |
Solution |
|
Easy |
|
625 |
Minimum Factorization |
Solution |
|
Medium |
|
624 |
Maximum Distance in Arrays |
Solution |
|
Easy |
Sort, Array |
623 |
Add One Row to Tree |
Solution |
|
Medium |
Tree |
622 |
Design Circular Queue |
Solution |
|
Medium |
Design, Queue |
621 |
Task Scheduler |
Solution |
|
Medium |
Greedy, Queue |
617 |
Merge Two Binary Trees |
Solution |
|
Easy |
Tree, Recursion |
616 |
Add Bold Tag in String |
Solution |
|
Medium |
String |
611 |
Valid Triangle Number |
Solution |
|
Medium |
Binary Search |
609 |
Find Duplicate File in System |
Solution |
|
Medium |
HashMap |
606 |
Construct String from Binary Tree |
Solution |
|
Easy |
Tree, Recursion |
605 |
Can Place Flowers |
Solution |
|
Easy |
Array |
604 |
Design Compressed String Iterator |
Solution |
|
Easy |
Design, String |
600 |
Non-negative Integers without Consecutive Ones |
Solution |
|
Hard |
Bit Manipulation, DP |
599 |
Minimum Index Sum of Two Lists |
Solution |
|
Easy |
HashMap |
598 |
Range Addition II |
Solution |
|
Easy |
|
594 |
Longest Harmonious Subsequence |
Solution |
|
Easy |
Array, HashMap |
593 |
Valid Square |
Solution, Javascript |
|
Medium |
Math |
592 |
Fraction Addition and Subtraction |
Solution |
|
Medium |
Math |
591 |
Tag Validator |
Solution |
|
Hard |
Stack, String |
590 |
N-ary Tree Postorder Traversal |
Solution |
|
Easy |
DFS, recursion |
589 |
N-ary Tree Preorder Traversal |
Solution |
|
Easy |
DFS, recursion |
588 |
Design In-Memory File System |
Solution |
|
Hard |
Trie, Design |
587 |
Erect the Fence |
Solution |
|
Hard |
Geometry |
583 |
Delete Operation for Two Strings |
Solution |
|
Medium |
DP |
582 |
Kill Process |
Solution |
|
Medium |
Stack |
581 |
Shortest Unsorted Continuous Subarray |
Solution |
|
Easy |
Array, Sort |
576 |
Out of Boundary Paths |
Solution |
|
Hard |
DP, DFS |
575 |
Distribute Candies |
Solution |
|
Easy |
Array |
573 |
Squirrel Simulation |
Solution |
|
Medium |
Math |
572 |
Subtree of Another Tree |
Solution |
|
Easy |
Tree |
568 |
Maximum Vacation Days |
Solution |
|
Hard |
DP |
567 |
Permutation in String |
Solution |
|
Medium |
Sliding Windows, Two Pointers |
566 |
Reshape the Matrix |
Solution |
|
Easy |
|
565 |
Array Nesting |
Solution |
|
Medium |
|
563 |
Binary Tree Tilt |
Solution |
|
Easy |
Tree Recursion |
562 |
Longest Line of Consecutive One in Matrix |
Solution |
|
Medium |
Matrix DP |
561 |
Array Partition I |
Solution |
|
Easy |
Array |
560 |
Subarray Sum Equals K |
Solution |
|
Medium |
Array, HashMap |
559 |
Maximum Depth of N-ary Tree |
Solution |
|
Easy |
DFS, recursion |
557 |
Reverse Words in a String III |
Solution |
|
Easy |
String |
556 |
Next Greater Element III |
Solution |
|
Medium |
String |
555 |
Split Concatenated Strings |
Solution |
|
Medium |
String |
554 |
Brick Wall |
Solution |
|
Medium |
HashMap |
553 |
Optimal Division |
Solution |
|
Medium |
String, Math |
552 |
Student Attendance Record II |
Solution |
|
Hard |
DP |
551 |
Student Attendance Record I |
Solution |
|
Easy |
String |
549 |
Binary Tree Longest Consecutive Sequence II |
Solution |
|
Medium |
Tree |
548 |
Split Array with Equal Sum |
Solution |
|
Medium |
Array |
547 |
Friend Circles |
Solution |
|
Medium |
Union Find |
546 |
Remove Boxes |
Solution |
|
Hard |
DFS, DP |
545 |
Boundary of Binary Tree |
Solution |
|
Medium |
Recursion |
544 |
Output Contest Matches |
Solution |
|
Medium |
Recursion |
543 |
Diameter of Binary Tree |
Solution |
|
Easy |
Tree/DFS/Recursion |
542 |
01 Matrix |
Solution |
|
Medium |
BFS |
541 |
Reverse String II |
Solution |
|
Easy |
String |
540 |
Single Element in a Sorted Array |
Solution |
|
Medium |
|
539 |
Minimum Time Difference |
Solution |
|
Medium |
String |
538 |
Convert BST to Greater Tree |
Solution |
|
Easy |
Tree |
537 |
Complex Number Multiplication |
Solution |
|
Medium |
Math, String |
536 |
Construct Binary Tree from String |
Solution |
|
Medium |
Recursion, Stack |
535 |
Encode and Decode TinyURL |
Solution |
|
Medium |
Design |
533 |
Lonely Pixel II |
Solution |
|
Medium |
HashMap |
532 |
K-diff Pairs in an Array |
Solution |
|
Easy |
HashMap |
531 |
Lonely Pixel I |
Solution |
|
Medium |
|
530 |
Minimum Absolute Difference in BST |
Solution |
|
Easy |
DFS |
529 |
Minesweeper |
Solution |
|
Medium |
BFS |
527 |
Word Abbreviation |
Solution |
|
Hard |
|
526 |
Beautiful Arrangement |
Solution |
|
Medium |
Backtracking |
525 |
Contiguous Array |
Solution |
|
Medium |
HashMap |
524 |
Longest Word in Dictionary through Deleting |
Solution |
|
Medium |
Sort |
523 |
Continuous Subarray Sum |
Solution |
|
Medium |
DP |
522 |
Longest Uncommon Subsequence II |
Solution |
|
Medium |
|
521 |
Longest Uncommon Subsequence I |
Solution |
|
Easy |
|
520 |
Detect Capital |
Solution |
|
Easy |
|
517 |
Super Washing Machines |
Solution |
|
Hard |
DP |
516 |
Longest Palindromic Subsequence |
Solution |
|
Medium |
DP |
515 |
Find Largest Value in Each Tree Row |
Solution |
|
Medium |
BFS |
514 |
Freedom Trail |
Solution |
|
Hard |
DP |
513 |
Find Bottom Left Tree Value |
Solution |
|
Medium |
BFS |
509 |
Fibonacci Number |
Solution |
๐บ |
Easy |
Array |
508 |
Most Frequent Subtree Sum |
Solution |
|
Medium |
DFS, Tree |
507 |
Perfect Number |
Solution |
|
Easy |
Math |
506 |
Relative Ranks |
Solution |
|
Easy |
|
505 |
The Maze II |
Solution |
|
Medium |
BFS |
504 |
Base 7 |
Solution |
|
Easy |
|
503 |
Next Greater Element II |
Solution |
|
Medium |
Stack |
502 |
IPO |
Solution |
|
Hard |
Heap, Greedy |
501 |
Find Mode in Binary Tree |
Solution |
|
Easy |
Binary Tree |
500 |
Keyboard Row |
Solution |
|
Easy |
|
499 |
The Maze III |
Solution |
|
Hard |
BFS |
496 |
Next Greater Element I |
Solution |
|
Easy |
|
498 |
Diagonal Traverse |
Solution |
|
Medium |
|
495 |
Teemo Attacking |
Solution |
|
Medium |
Array |
494 |
Target Sum |
Solution |
|
Medium |
|
493 |
Reverse Pairs |
Solution |
|
Hard |
Recursion |
492 |
Construct the Rectangle |
Solution |
|
Easy |
Array |
491 |
Increasing Subsequences |
Solution |
|
Medium |
Backtracking, DFS |
490 |
The Maze |
Solution |
|
Medium |
BFS |
488 |
Zuma Game |
Solution |
|
Hard |
DFS, Backtracking |
487 |
Max Consecutive Ones II |
Solution |
๐บ |
Medium |
Array |
486 |
Predict the Winner |
Solution |
|
Medium |
DP |
485 |
Max Consecutive Ones |
Java Javascript |
๐บ |
Easy |
Array |
484 |
Find Permutation |
Solution |
|
Medium |
Array, String, Greedy |
483 |
Smallest Good Base |
Solution |
|
Hard |
Binary Search, Math |
482 |
License Key Formatting |
Solution |
|
Medium |
|
481 |
Magical String |
Solution |
|
Medium |
|
480 |
Sliding Window Median |
Solution |
|
Hard |
Heap |
479 |
Largest Palindrome Product |
Solution |
|
Easy |
|
477 |
Total Hamming Distance |
Solution |
|
Medium |
Bit Manipulation |
478 |
Generate Random Point in a Circle |
Solution |
|
Medium |
Math, Random, Rejection Sampling |
476 |
Number Complement |
Solution |
|
Easy |
Bit Manipulation |
475 |
Heaters |
Solution |
|
Easy |
Array Binary Search |
474 |
Ones and Zeroes |
Solution |
|
Medium |
DP |
473 |
Matchsticks to Square |
Solution |
|
Medium |
Backtracking, DFS |
472 |
Concatenated Words |
Solution |
|
Hard |
Trie, DP, DFS |
471 |
Encode String with Shortest Length |
Solution |
|
Hard |
DP |
469 |
Convex Polygon |
Solution |
|
Medium |
Math |
468 |
Validate IP Address |
Solution |
|
Medium |
String |
467 |
Unique Substrings in Wraparound String |
Solution |
|
Medium |
DP |
466 |
Count The Repetitions |
Solution |
|
Hard |
DP |
465 |
Optimal Account Balancing |
Solution |
|
Hard |
DP |
464 |
Can I Win |
Solution |
|
Medium |
DP |
463 |
Island Perimeter |
Solution |
|
Easy |
|
462 |
Minimum Moves to Equal Array Elements II |
Solution |
|
Medium |
|
461 |
Hamming Distance |
Solution, C++ |
|
Easy |
|
460 |
LFU Cache |
Solution |
|
Hard |
Design, LinkedHashMap, HashMap |
459 |
Repeated Substring Pattern |
Solution |
|
Easy |
String, KMP |
458 |
Poor Pigs |
Solution |
|
Easy |
Math |
457 |
Circular Array Loop |
Solution |
|
Medium |
|
456 |
132 Pattern |
Solution |
|
Medium |
Stack |
455 |
Assign Cookies |
Solution |
|
Easy |
|
454 |
4Sum II |
Solution |
|
Medium |
HashMap |
453 |
Minimum Moves to Equal Array Elements |
Solution |
|
Easy |
|
452 |
Minimum Number of Arrows to Burst Balloons |
Solution |
|
Medium |
Array, Greedy |
451 |
Sort Characters By Frequency |
Solution |
|
Medium |
HashMap |
450 |
Delete Node in a BST |
Solution |
|
Medium |
Tree, Recursion |
449 |
Serialize and Deserialize BST |
Solution |
|
Medium |
BFS |
448 |
Find All Numbers Disappeared in an Array |
Solution |
|
Easy |
Array, HashMap |
447 |
Number of Boomerangs |
Solution |
|
Easy |
HashMap |
446 |
Arithmetic Slices II - Subsequence |
Solution |
|
Hard |
DP |
445 |
Add Two Numbers II |
Solution |
|
Medium |
Stack, LinkedList |
444 |
Sequence Reconstruction |
Solution |
|
Medium |
Topological Sort, Graph |
443 |
String Compression |
Solution |
|
Easy |
|
442 |
Find All Duplicates in an Array |
Solution |
|
Medium |
Array |
441 |
Arranging Coins |
Solution |
|
Easy |
|
440 |
K-th Smallest in Lexicographical Order |
Solution |
|
Hard |
|
439 |
Ternary Expression Parser |
Solution |
|
Medium |
Stack |
438 |
Find All Anagrams in a String |
Solution |
|
Easy |
Sliding Window |
437 |
Path Sum III |
Solution |
|
Easy |
DFS, recursion |
436 |
Find Right Interval |
Solution |
|
Medium |
Binary Search |
435 |
Non-overlapping Intervals |
Solution |
|
Medium |
Greedy |
434 |
Number of Segments in a String |
Solution |
|
Easy |
|
432 |
All O`one Data Structure |
Solution |
|
Hard |
Design |
429 |
N-ary Tree Level Order Traversal |
Solution |
|
Easy |
BFS, Tree |
425 |
Word Squares |
Solution |
|
Hard |
Trie, Backtracking, Recursion |
424 |
Longest Repeating Character Replacement |
Solution |
|
Medium |
Sliding Window |
423 |
Reconstruct Original Digits from English |
Solution |
|
Medium |
Math |
422 |
Valid Word Square |
Solution |
|
Easy |
|
421 |
Maximum XOR of Two Numbers in an Array |
Solution |
|
Medium |
Bit Manipulation, Trie |
420 |
Strong Password Checker |
Solution |
|
Hard |
|
419 |
Battleships in a Board |
Solution |
|
Medium |
DFS |
418 |
Sentence Screen Fitting |
Solution |
|
Medium |
|
417 |
Pacific Atlantic Water Flow |
Solution |
|
Medium |
DFS |
416 |
Partition Equal Subset Sum |
Java, C++ |
|
Medium |
DP |
415 |
Add Strings |
Solution |
|
Easy |
|
414 |
Third Maximum Number |
Solution |
|
Easy |
|
413 |
Arithmetic Slices |
Solution |
|
Medium |
DP |
412 |
Fizz Buzz |
Solution |
|
Easy |
|
411 |
Minimum Unique Word Abbreviation |
Solution |
|
Hard |
NP-Hard, Backtracking, Trie, Recursion |
410 |
Split Array Largest Sum |
Solution |
|
Hard |
Binary Search, DP |
409 |
Longest Palindrome |
Solution |
|
Easy |
|
408 |
Valid Word Abbreviation |
Solution |
|
Easy |
|
407 |
Trapping Rain Water II |
Solution |
|
Hard |
Heap |
406 |
Queue Reconstruction by Height |
Solution |
|
Medium |
LinkedList, PriorityQueue |
405 |
Convert a Number to Hexadecimal |
Solution |
|
Easy |
|
404 |
Sum of Left Leaves |
Solution |
|
Easy |
|
403 |
Frog Jump |
Solution |
|
Hard |
DP |
402 |
Remove K Digits |
Solution |
|
Medium |
Greedy, Stack |
401 |
Binary Watch |
Solution |
|
Easy |
|
400 |
Nth Digit |
Solution |
|
Easy |
|
399 |
Evaluate Division |
Solution |
|
Medium |
Graph, DFS, Backtracking |
398 |
Random Pick Index |
Solution |
|
Medium |
Reservoir Sampling |
397 |
Integer Replacement |
Solution |
|
Easy |
BFS |
396 |
Rotate Function |
Solution |
|
Easy |
|
395 |
Longest Substring with At Least K Repeating Characters |
Solution |
|
Medium |
Recursion |
394 |
Decode String |
Solution |
|
Medium |
Stack Depth-first-search |
393 |
UTF-8 Validation |
Solution |
|
Medium |
Bit Manipulation |
392 |
Is Subsequence |
Solution |
|
Medium |
Array, String |
391 |
Perfect Rectangle |
Solution |
|
Hard |
|
390 |
Elimination Game |
Solution |
|
Medium |
|
389 |
Find the Difference |
Solution |
|
|
Easy |
388 |
Longest Absolute File Path |
Solution |
|
Medium |
Stack |
387 |
First Unique Character in a String |
Solution |
|
Easy |
HashMap |
386 |
Lexicographical Numbers |
Solution |
|
Medium |
|
385 |
Mini Parser |
Solution |
|
Medium |
Stack |
384 |
Shuffle an Array |
Solution |
|
Medium |
|
383 |
Ransom Note |
Solution |
|
Easy |
String |
382 |
Linked List Random Node |
Solution |
|
Medium |
Reservoir Sampling |
381 |
Insert Delete GetRandom O(1) - Duplicates allowed |
Solution |
|
Hard |
|
380 |
Insert Delete GetRandom O(1) |
Solution |
|
Medium |
Design, HashMap |
379 |
Design Phone Directory |
Solution |
|
Medium |
|
378 |
Kth Smallest Element in a Sorted Matrix |
Solution |
|
Medium |
Binary Search |
377 |
Combination Sum IV |
Solution |
|
Medium |
DP |
376 |
Wiggle Subsequence |
Solution |
|
Medium |
DP, Greedy |
375 |
Guess Number Higher or Lower II |
Solution |
|
Medium |
DP |
374 |
Guess Number Higher or Lower |
Solution |
|
Easy |
Binary Search |
373 |
Find K Pairs with Smallest Sums |
Solution |
|
Medium |
Heap |
372 |
Super Pow |
Solution |
|
Medium |
Math |
371 |
Sum of Two Integers |
Solution |
|
Easy |
|
370 |
Range Addition |
Solution |
|
Medium |
Array |
369 |
Plus One Linked List |
Solution |
|
Medium |
Linked List |
368 |
Largest Divisible Subset |
Solution |
|
Medium |
DP |
367 |
Valid Perfect Square |
Solution |
|
Medium |
|
366 |
Find Leaves of Binary Tree |
Solution |
|
Medium |
DFS |
365 |
Water and Jug Problem |
Solution |
|
Medium |
Math |
364 |
Nested List Weight Sum II |
Solution |
|
Medium |
DFS |
363 |
Max Sum of Rectangle No Larger Than K |
Solution |
|
Hard |
DP |
362 |
Design Hit Counter |
Solution |
|
Medium |
Design |
361 |
Bomb Enemy |
Solution |
|
Medium |
|
360 |
Sort Transformed Array |
Solution |
|
Medium |
Two Pointers, Math |
359 |
Logger Rate Limiter |
Solution |
|
Easy |
HashMap |
358 |
Rearrange String k Distance Apart |
Solution |
|
Hard |
HashMap, Heap, Greedy |
357 |
Count Numbers with Unique Digits |
Solution |
|
Medium |
DP, Math |
356 |
Line Reflection |
Solution |
|
Medium |
HashSet |
355 |
Design Twitter |
Solution |
|
Medium |
Design, HashMap, Heap |
354 |
Russian Doll Envelopes |
Solution |
|
Hard |
DP, Binary Search |
353 |
Design Snake Game |
Solution |
|
Medium |
|
352 |
Data Stream as Disjoint Intervals |
Solution |
|
Hard |
TreeMap |
351 |
Android Unlock Patterns |
Solution |
|
Medium |
|
350 |
Intersection of Two Arrays II |
Solution |
๐บ |
Easy |
HashMap, Binary Search |
349 |
Intersection of Two Arrays |
Solution |
๐บ |
Easy |
Two Pointers, Binary Search |
348 |
Design Tic-Tac-Toe |
Solution |
|
Medium |
Design |
347 |
Top K Frequent Elements |
Solution |
|
Medium |
HashTable, Heap, Bucket Sort |
346 |
Moving Average from Data Stream |
Solution |
|
Easy |
Queue |
345 |
Reverse Vowels of a String |
Solution |
|
Easy |
String |
344 |
Reverse String |
Solution |
๐บ |
Easy |
String |
343 |
Integer Break |
Solution |
|
Medium |
Math |
342 |
Power of Four |
Solution |
|
Easy |
Math |
341 |
Flatten Nested List Iterator |
Solution |
|
Medium |
Stack |
340 |
Longest Substring with At Most K Distinct Characters |
Solution |
|
Hard |
Sliding Window |
339 |
Nested List Weight Sum |
Solution |
|
Easy |
DFS |
338 |
Counting Bits |
Solution |
|
Medium |
|
337 |
House Robber III |
Solution |
|
Medium |
DP |
336 |
Palindrome Pairs |
Solution |
|
Hard |
|
335 |
Self Crossing |
Solution |
|
Hard |
Math |
334 |
Increasing Triplet Subsequence |
Solution |
|
Medium |
|
333 |
Largest BST Subtree |
Solution |
|
Medium |
Tree |
332 |
Reconstruct Itinerary |
Solution |
|
Medium |
Graph, DFS |
331 |
Verify Preorder Serialization of a Binary Tree |
Solution |
|
Medium |
Stack |
330 |
Patching Array |
Solution |
|
Hard |
Greedy |
329 |
Longest Increasing Path in a Matrix |
Solution |
|
Hard |
DFS, DP |
328 |
Odd Even Linked List |
Solution |
|
Medium |
Linked List |
327 |
Count of Range Sum |
Solution |
|
Hard |
BST, Divide and Conquer |
326 |
Power of Three |
Solution |
|
Easy |
Math |
325 |
Maximum Size Subarray Sum Equals k |
Solution |
|
Medium |
HashTable |
324 |
Wiggle Sort II |
Solution |
|
Medium |
Sort |
323 |
Number of Connected Components in an Undirected Graph |
Solution |
|
Medium |
|
322 |
Coin Change |
Solution |
|
Medium |
DP |
321 |
Create Maximum Number |
Solution |
|
Hard |
|
320 |
Generalized Abbreviation |
Solution |
|
Medium |
Backtracking, Bit Manipulation |
319 |
Bulb Switcher |
Solution |
|
Medium |
Brainteaser |
318 |
Maximum Product of Word Lengths |
Solution |
|
Medium |
|
317 |
Shortest Distance from All Buildings |
Solution |
|
Hard |
|
316 |
Remove Duplicate Letters |
Solution |
|
Hard |
Stack, Recursion, Greedy |
315 |
Count of Smaller Numbers After Self |
Solution |
|
Hard |
Tree |
314 |
Binary Tree Vertical Order Traversal |
Solution |
|
Medium |
HashMap, BFS |
313 |
Super Ugly Number |
Solution |
|
Medium |
|
312 |
Burst Balloons |
Solution |
|
Hard |
DP |
311 |
Sparse Matrix Multiplication |
Solution |
|
Medium |
|
310 |
Minimum Height Trees |
Solution |
|
Medium |
|
309 |
Best Time to Buy and Sell Stock with Cooldown |
Solution |
|
Medium |
DP |
308 |
Range Sum Query 2D - Mutable |
Solution |
|
Hard |
Tree |
307 |
Range Sum Query - Mutable |
Solution |
|
Medium |
Tree |
306 |
Additive Number |
Solution |
|
Medium |
|
305 |
Number of Islands II |
Solution |
|
Hard |
Union Find |
304 |
Range Sum Query 2D - Immutable |
Solution |
|
Medium |
|
303 |
Range Sum Query - Immutable |
Solution |
|
Easy |
|
302 |
Smallest Rectangle Enclosing Black Pixels |
Solution |
|
Hard |
DFS, BFS |
301 |
Remove Invalid Parentheses |
Solution |
|
Hard |
BFS |
300 |
Longest Increasing Subsequence |
Solution |
|
Medium |
DP |
299 |
Bulls and Cows |
Solution |
|
Easy |
|
298 |
Binary Tree Longest Consecutive Sequence |
Solution |
|
Medium |
Tree |
297 |
Serialize and Deserialize Binary Tree |
Solution |
|
Hard |
BFS |
296 |
Best Meeting Point |
Solution |
|
Hard |
|
295 |
Find Median from Data Stream |
Solution |
|
Hard |
Heap |
294 |
Flip Game II |
Solution |
|
Medium |
Backtracking |
293 |
Flip Game |
Solution |
|
Easy |
|
292 |
Nim Game |
Solution |
|
Easy |
|
291 |
Word Pattern II |
Solution |
|
Hard |
Recursion, Backtracking |
290 |
Word Pattern |
Solution |
|
Easy |
HashMap |
289 |
Game of Life |
Solution |
๐บ |
Medium |
|
288 |
Unique Word Abbreviation |
Solution |
|
Easy |
|
287 |
Find the Duplicate Number |
Solution |
|
Medium |
|
286 |
Walls and Gates |
Solution |
|
Medium |
BFS |
285 |
Inorder Successor In BST |
Solution |
|
Medium |
Tree |
284 |
Peeking Iterator |
Solution |
|
Medium |
Design |
283 |
Move Zeroes |
Solution |
๐บ |
Easy |
|
282 |
Expression Add Operators |
Solution |
|
Hard |
|
281 |
Zigzag Iterator |
Solution |
|
Medium |
|
280 |
Wiggle Sort |
Solution |
|
Medium |
|
279 |
Perfect Squares |
Solution |
|
Medium |
|
278 |
First Bad Version |
Solution |
๐บ |
Easy |
Binary Search |
277 |
Find the Celebrity |
Solution |
|
Medium |
|
276 |
Paint Fence |
Solution |
|
Easy |
DP |
275 |
H-Index II |
Solution |
|
Medium |
Binary Search |
274 |
H-Index |
Solution |
|
Medium |
|
273 |
Integer to English Words |
Solution |
|
Hard |
Math, String |
272 |
Closest Binary Search Tree Value II |
Solution |
|
Hard |
Stack |
271 |
Encode and Decode Strings |
Solution |
|
|
Medium |
270 |
Closest Binary Search Tree Value |
Solution |
|
|
Easy |
269 |
Alien Dictionary |
Solution |
|
|
Hard |
268 |
Missing Number |
Solution |
|
|
Easy |
267 |
Palindrome Permutation II |
Solution |
|
Medium |
|
266 |
Palindrome Permutation |
Solution |
|
Easy |
|
265 |
Paint House II |
Solution |
|
Hard |
DP |
264 |
Ugly Number II |
Solution |
|
Medium |
DP |
263 |
Ugly Number |
Solution |
|
Easy |
|
261 |
Graph Valid Tree |
Solution |
|
Medium |
|
260 |
Single Number III |
Solution |
|
Medium |
|
259 |
3Sum Smaller |
Solution |
|
Medium |
|
258 |
Add Digits |
Solution |
|
Easy |
|
257 |
Binary Tree Paths |
Solution |
|
|
DFS/Recursion |
256 |
Paint House |
Solution |
|
Medium |
DP |
255 |
Verify Preorder Sequence in Binary Search Tree |
Solution |
|
Medium |
Tree |
254 |
Factor Combinations |
Solution |
|
Medium |
Backtracking |
253 |
Meeting Rooms II |
Solution |
|
Medium |
Heap |
252 |
Meeting Rooms |
Solution |
|
Easy |
|
251 |
Flatten 2D Vector |
Solution |
|
Medium |
|
250 |
Count Univalue Subtrees |
Solution |
|
Medium |
DFS |
249 |
Group Shifted Strings |
Solution |
|
|
|
248 |
Strobogrammatic Number III |
Solution |
|
Hard |
Recursion, DFS |
247 |
Strobogrammatic Number II |
Solution |
|
Medium |
Recursion |
246 |
Strobogrammatic Number |
Solution |
|
Easy |
|
245 |
Shortest Word Distance III |
Solution |
|
Medium |
|
244 |
Shortest Word Distance II |
Solution |
|
Medium |
HashMap |
243 |
Shortest Word Distance |
Solution |
|
Easy |
|
242 |
Valid Anagram |
Solution |
|
Easy |
|
241 |
Different Ways to Add Parentheses |
Solution |
|
Medium |
Divide and Conquer |
240 |
Search a 2D Matrix II |
Solution |
|
Medium |
Binary Search |
239 |
Sliding Window Maximum |
Solution |
|
Hard |
Heap |
238 |
Product of Array Except Self |
Solution |
|
Medium |
Array |
237 |
Delete Node in a Linked List |
Solution |
๐บ |
Easy |
LinkedList |
236 |
Lowest Common Ancestor of a Binary Tree |
Solution |
|
Medium |
DFS |
235 |
Lowest Common Ancestor of a Binary Search Tree |
Solution |
|
Easy |
DFS |
234 |
Palindrome Linked List |
Solution |
๐บ |
Easy |
Linked List |
233 |
Number of Digit One |
Solution |
|
Hard |
Math |
232 |
Implement Queue using Stacks |
Solution |
|
Medium |
Stack, Design |
231 |
Power of Two |
Solution |
|
Easy |
|
230 |
Kth Smallest Element in a BST |
Solution |
|
Medium |
Tree |
229 |
Majority Element II |
Solution |
|
Medium |
|
228 |
Summary Ranges |
Solution |
|
Medium |
Array |
227 |
Basic Calculator II |
Solution |
|
Medium |
String |
226 |
Invert Binary Tree |
Solution |
|
Easy |
DFS, recursion |
225 |
Implement Stack using Queues |
Solution |
|
Easy |
Stack, Queue |
224 |
Basic Calculator |
Solution |
|
Hard |
|
223 |
Rectangle Area |
Solution |
|
Easy |
|
222 |
Count Complete Tree Nodes |
Solution |
|
Medium |
Recursion |
221 |
Maximal Square |
Solution |
|
Medium |
Recursion |
220 |
Contains Duplicate III |
Solution |
๐บ |
Medium |
TreeSet |
219 |
Contains Duplicate II |
Solution |
๐บ |
Easy |
HashMap |
218 |
The Skyline Problem |
Solution |
|
Hard |
TreeMap, Design |
217 |
Contains Duplicate |
Solution |
๐บ |
Easy |
HashSet |
216 |
Combination Sum III |
Solution |
|
Medium |
Backtracking |
215 |
Kth Largest Element in an Array |
Solution |
|
Medium |
Heap |
214 |
Shortest Palindrome |
Solution |
|
Hard |
KMP |
213 |
House Robber II |
Solution |
|
Medium |
DP |
212 |
Word Search II |
Solution |
|
Hard |
Trie |
211 |
Add and Search Word - Data structure design |
Solution |
|
Medium |
Trie |
210 |
Course Schedule II |
Solution |
|
Medium |
|
209 |
Minimum Size Subarray Sum |
Solution |
|
Medium |
|
208 |
Implement Trie |
Solution |
๐บ |
Medium |
Trie |
207 |
Course Schedule |
Solution |
|
Medium |
|
206 |
Reverse Linked List |
Solution |
๐บ |
Easy |
Linked List |
205 |
Isomorphic Strings |
Solution |
|
Easy |
|
204 |
Count Primes |
Solution |
|
Easy |
The Sieve of Eratosthenes |
203 |
Remove Linked List Elements |
Solution |
|
Easy |
|
202 |
Happy Number |
Solution |
|
Easy |
|
201 |
Bitwise AND of Numbers Range |
Solution |
|
Medium |
Bit Manipulation |
200 |
Number of Islands |
Solution |
|
Medium |
Union Find, DFS |
199 |
Binary Tree Right Side View |
Solution |
|
Medium |
BFS |
198 |
House Robber |
Solution |
|
Easy |
DP |
191 |
Number of 1 Bits |
Solution |
|
Easy |
Bit Manipulation |
190 |
Reverse Bits |
Solution |
|
Easy |
Bit Manipulation |
189 |
Rotate Array |
Solution |
๐บ |
Easy |
|
188 |
Best Time to Buy and Sell Stock IV |
Solution |
|
Hard |
DP |
187 |
Repeated DNA Sequences |
Solution |
|
Medium |
|
186 |
Reverse Words in a String II |
Solution |
|
Medium |
|
179 |
Largest Number |
Solution |
|
Medium |
|
174 |
Dungeon Game |
Solution |
|
Hard |
DP |
173 |
Binary Search Tree Iterator |
Solution |
|
Medium |
Stack, Design |
172 |
Factorial Trailing Zeroes |
Solution |
|
Easy |
|
171 |
Excel Sheet Column Number |
Solution |
|
Easy |
|
170 |
Two Sum III - Data structure design |
Solution |
|
Easy |
|
169 |
Majority Element |
Solution |
๐บ |
Easy |
|
168 |
Excel Sheet Column Title |
Solution |
|
Easy |
|
167 |
Two Sum II - Input array is sorted |
Java, Javascript |
|
Easy |
Binary Search |
166 |
Fraction to Recurring Decimal |
Solution |
|
Medium |
HashMap |
165 |
Compare Version Numbers |
Solution |
|
Easy |
|
164 |
Maximum Gap |
Solution |
|
Hard |
|
163 |
Missing Ranges |
Solution |
|
|
|
162 |
Find Peak Element |
Solution |
|
Binary Search |
|
161 |
One Edit Distance |
Solution |
|
|
|
160 |
Intersection of Two Linked Lists |
Solution |
|
Easy |
Linked List |
159 |
Longest Substring with At Most Two Distinct Characters |
Solution |
|
Hard |
String, Sliding Window |
158 |
Read N Characters Given Read4 II - Call multiple times |
Solution |
|
Hard |
|
157 |
Read N Characters Given Read4 |
Solution |
|
Easy |
|
156 |
Binary Tree Upside Down |
Solution |
|
Medium |
Tree, Recursion |
155 |
Min Stack |
Solution |
|
Easy |
Stack |
154 |
Find Minimum in Rotated Sorted Array II |
Solution |
|
Hard |
Array, Binary Search |
153 |
Find Minimum in Rotated Sorted Array |
Solution |
|
Medium |
Array, Binary Search |
152 |
Maximum Product Subarray |
Solution |
|
Medium |
Array |
151 |
Reverse Words in a String |
Solution |
|
Medium |
String |
150 |
Evaluate Reverse Polish Notation |
Solution |
|
Medium |
|
149 |
Max Points on a Line |
Solution |
|
Hard |
|
147 |
Insertion Sort List |
Solution |
|
Medium |
Linked List |
146 |
LRU Cache |
Solution |
|
Hard |
Doubly Linked List, LinkedHashMap |
145 |
Binary Tree Postorder Traversal |
Solution |
๐บ |
Hard |
Binary Tree |
144 |
Binary Tree Preorder Traversal |
Solution |
๐บ and ๐บ |
Medium |
Binary Tree |
143 |
Reorder List |
Solution |
|
Medium |
|
142 |
Linked List Cycle II |
Solution |
|
Medium |
Linked List |
141 |
Linked List Cycle |
Solution |
๐บ |
Easy |
Linked List |
140 |
Word Break II |
Solution |
|
Hard |
Backtracking/DFS |
139 |
Word Break |
Solution |
๐บ |
Medium |
DP, Pruning |
138 |
Copy List with Random Pointer |
Solution |
|
Medium |
LinkedList, HashMap |
137 |
Single Number II |
Solution |
|
Medium |
Bit Manipulation |
136 |
Single Number |
Solution |
๐บ |
Easy |
Bit Manipulation |
135 |
Candy |
Solution |
|
Hard |
Greedy |
134 |
Gas Station |
Solution |
|
Medium |
Greedy |
133 |
Clone Graph |
Solution |
|
Medium |
HashMap, BFS, Graph |
132 |
Palindrome Partitioning II |
Solution |
|
Hard |
|
131 |
Palindrome Partitioning |
Solution |
|
Medium |
|
130 |
Surrounded Regions |
Solution |
|
Medium |
|
129 |
Sum Root to Leaf Numbers |
Solution |
|
Medium |
DFS |
128 |
Longest Consecutive Sequence |
Solution |
|
Hard |
Union Find |
127 |
Word Ladder |
Solution |
|
Hard |
BFS |
126 |
Word Ladder II |
Solution |
|
Hard |
BFS |
125 |
Valid Palindrome |
Solution |
|
Easy |
Two Pointers |
124 |
Binary Tree Maximum Path Sum |
Solution |
|
Hard |
Tree, DFS |
123 |
Best Time to Buy and Sell Stock III |
Solution |
|
Hard |
DP |
122 |
Best Time to Buy and Sell Stock II |
Solution |
|
Easy |
Greedy |
121 |
Best Time to Buy and Sell Stock |
Solution |
|
Easy |
|
120 |
Triangle |
Solution |
|
Medium |
DP |
119 |
Pascal's Triangle II |
Solution |
๐บ |
Easy |
|
118 |
Pascal's Triangle |
Solution |
๐บ |
Easy |
|
117 |
Populating Next Right Pointers in Each Node II |
Solution |
|
Medium |
BFS |
116 |
Populating Next Right Pointers in Each Node |
Solution |
|
Medium |
BFS |
115 |
Distinct Subsequences |
Solution |
|
Hard |
DP |
114 |
Flatten Binary Tree to Linked List |
Solution |
|
Medium |
Tree |
113 |
Path Sum II |
Solution |
|
Medium |
DFS, Backtracking |
112 |
Path Sum |
Solution |
|
Easy |
DFS |
111 |
Minimum Depth of Binary Tree |
Solution |
|
Easy |
BFS, DFS |
110 |
Balanced Binary Tree |
Solution |
|
Easy |
DFS |
109 |
Convert Sorted List to Binary Search Tree |
Solution |
|
Medium |
DFS, Recursion |
108 |
Convert Sorted Array to Binary Search Tree |
Solution |
๐บ |
Easy |
Tree |
107 |
Binary Tree Level Order Traversal II |
Solution |
|
Easy |
BFS |
106 |
Construct Binary Tree from Inorder and Postorder Traversal |
Solution |
|
Medium |
Recursion, Tree |
105 |
Construct Binary Tree from Preorder and Inorder Traversal |
Solution |
|
Medium |
Recursion, Tree |
104 |
Maximum Depth of Binary Tree |
Solution |
๐บ |
Easy |
DFS |
103 |
Binary Tree Zigzag Level Order Traversal |
Solution |
|
Medium |
BFS,DFS |
102 |
Binary Tree Level Order Traversal |
Solution |
๐บ |
Medium |
BFS |
101 |
Symmetric Tree |
Solution |
๐บ |
Easy |
DFS |
100 |
Same Tree |
Solution |
๐บ |
Easy |
DFS |
99 |
Recover Binary Search Tree |
Solution |
|
Hard |
|
98 |
Validate Binary Search Tree |
Solution |
๐บ |
Medium |
DFS/Recursion |
97 |
Interleaving String |
Solution |
|
Hard |
DP |
96 |
Unique Binary Search Trees |
Solution |
|
Medium |
Recursion, DP |
95 |
Unique Binary Search Trees II |
Solution |
|
Medium |
Recursion |
94 |
Binary Tree Inorder Traversal |
Solution |
๐บ ๐บ |
Medium |
Binary Tree |
93 |
Restore IP Addresses |
Solution |
|
Medium |
Backtracking |
92 |
Reverse Linked List II |
Solution |
|
Medium |
|
91 |
Decode Ways |
Solution |
|
Medium |
DP |
90 |
Subsets II |
Solution |
|
Medium |
Backtracking |
89 |
Gray Code |
Solution |
|
Medium |
Bit Manipulation |
88 |
Merge Sorted Array |
Solution |
|
Easy |
|
87 |
Scramble String |
Solution |
|
Hard |
Recursion |
86 |
Partition List |
Solution |
|
Medium |
Linked List |
85 |
Maximal Rectangle |
Solution |
|
Hard |
DP |
84 |
Largest Rectangle in Histogram |
Solution |
|
Hard |
Array, Stack |
83 |
Remove Duplicates from Sorted List |
Solution |
|
Easy |
Linked List |
82 |
Remove Duplicates from Sorted List II |
Solution |
|
Medium |
Linked List |
81 |
Search in Rotated Sorted Array II |
Solution |
|
Medium |
Binary Search |
80 |
Remove Duplicates from Sorted Array II |
Solution |
|
Medium |
|
79 |
Word Search |
Solution |
|
Medium |
Backtracking, DFS |
78 |
Subsets |
Solution |
|
Medium |
Backtracking |
77 |
Combinations |
Solution |
|
Medium |
Backtracking |
76 |
Minimum Window Substring |
Solution |
|
Hard |
Two Pointers |
75 |
Sort Colors |
Solution |
|
Medium |
Two Pointers |
74 |
Search a 2D Matrix |
Solution |
|
Medium |
Binary Search |
73 |
Set Matrix Zeroes |
Solution |
|
Medium |
|
72 |
Edit Distance |
Solution |
|
Hard |
|
71 |
Simplify Path |
Solution |
|
Medium |
Stack |
70 |
Climbing Stairs |
Solution |
๐บ |
Easy |
DP |
69 |
Sqrt(x) |
Solution |
|
Easy |
|
68 |
Text Justification |
Solution |
|
Hard |
|
67 |
Add Binary |
Solution |
|
Easy |
|
66 |
Plus One |
Solution |
๐บ |
Easy |
|
65 |
Valid Number |
Solution |
|
Hard |
|
64 |
Minimum Path Sum |
Solution |
|
Medium |
DP |
63 |
Unique Paths II |
Solution |
|
Medium |
DP |
62 |
Unique Paths |
Solution |
|
Medium |
DP |
61 |
Rotate List |
Solution |
|
Medium |
Linked List |
60 |
Permutation Sequence |
Solution |
|
Medium |
Math, Backtracking |
59 |
Spiral Matrix II |
Solution |
๐บ |
Medium |
|
58 |
Length of Last Word |
Solution |
|
Easy |
|
57 |
Insert Intervals |
Solution |
|
Hard |
Array, Sort |
56 |
Merge Intervals |
Solution |
|
Medium |
Array, Sort |
55 |
Jump Game |
Solution |
|
Medium |
Greedy |
54 |
Spiral Matrix |
Solution |
๐บ |
Medium |
Array |
53 |
Maximum Subarray |
Solution |
|
Easy |
Array |
52 |
N-Queens II |
Solution |
|
Hard |
Backtracking |
51 |
N-Queens |
Solution |
|
Hard |
|
50 |
Pow(x, n) |
Solution |
|
Medium |
|
49 |
Group Anagrams |
Solution |
|
Medium |
HashMap |
48 |
Rotate Image |
Solution |
๐บ |
Medium |
Array |
47 |
Permutations II |
Solution |
|
Medium |
Backtracking |
46 |
Permutations |
Solution |
|
Medium |
Backtracking |
45 |
Jump Game II |
Solution |
|
Hard |
Array, Greedy |
44 |
Wildcard Matching |
Solution |
|
Hard |
Backtracking, DP, Greedy, String |
43 |
Multiply Strings |
Solution |
|
Medium |
Array, String |
42 |
Trapping Rain Water |
Solution |
|
Hard |
|
41 |
First Missing Positive |
Solution |
|
Hard |
Array |
40 |
Combination Sum II |
Solution |
|
Medium |
Backtracking |
39 |
Combination Sum |
Solution |
|
Medium |
Backtracking |
38 |
Count and Say |
Solution |
|
Easy |
Recursion, LinkedList |
37 |
Sudoku Solver |
Solution |
|
Hard |
|
36 |
Valid Sudoku |
Solution, Javascript |
|
Medium |
|
35 |
Search Insert Position |
Solution |
|
Easy |
Array |
34 |
Search for a Range |
Solution |
|
Medium |
Array, Binary Search |
33 |
Search in Rotated Sorted Array |
Solution |
|
Medium |
Binary Search |
32 |
Longest Valid Parentheses |
Solution |
|
Hard |
Stack, DP |
31 |
Next Permutation |
Solution, C++ |
|
Medium |
Array |
30 |
Substring with Concatenation of All Words |
Solution |
|
Hard |
HashMap |
29 |
Divide Two Integers |
Solution |
|
Medium |
|
28 |
Implement strStr() |
Solution |
|
Easy |
String |
27 |
Remove Element |
Solution |
|
Easy |
|
26 |
Remove Duplicates from Sorted Array |
Solution |
๐บ |
Easy |
Array |
25 |
Reverse Nodes in k-Group |
Solution |
|
Hard |
Recursion, LinkedList |
24 |
Swap Nodes in Pairs |
Solution |
|
Medium |
Recursion, LinkedList |
23 |
Merge k Sorted Lists |
Solution |
๐บ |
Hard |
Heap |
22 |
Generate Parentheses |
Solution |
|
Medium |
Backtracking |
21 |
Merge Two Sorted Lists |
Solution |
๐บ |
Easy |
Recursion |
20 |
Valid Parentheses |
Solution |
๐บ |
Easy |
Stack |
19 |
Remove Nth Node From End of List |
Solution |
๐บ |
Medium |
Linked List |
18 |
4 Sum |
Solution |
|
Medium |
Two Pointers |
17 |
Letter Combinations of a Phone Number |
Solution |
|
Medium |
Backtracking |
16 |
3Sum Closest |
Solution |
|
Medium |
Two Pointers |
15 |
3Sum |
Solution, C++ |
๐บ |
Medium |
Two Pointers, Binary Search |
14 |
Longest Common Prefix |
Solution |
๐บ |
Easy |
|
13 |
Roman to Integer |
Solution |
|
Easy |
Math, String |
12 |
Integer to Roman |
Solution |
|
Medium |
Math, String |
11 |
Container With Most Water |
Solution |
|
Medium |
|
10 |
Regular Expression Matching |
Java, Javascript |
|
Hard |
DP |
9 |
Palindrome Number |
Java, C++ |
|
Easy |
|
8 |
String to Integer (atoi) |
Solution |
|
Medium |
|
7 |
Reverse Integer |
Solution, C++ |
๐บ |
Easy |
|
6 |
ZigZag Conversion |
Solution |
|
Easy |
|
5 |
Longest Palindromic Substring |
Solution |
|
Medium |
|
4 |
Median of Two Sorted Arrays |
Solution, C++ |
|
Hard |
Divide and Conquer |
3 |
Longest Substring Without Repeating Characters |
Solution, C++ |
|
Medium |
HashMap, Sliding Window |
2 |
Add Two Numbers |
Solution |
|
Medium |
LinkedList |
1 |
Two Sum |
Java, C++, Javascript |
๐บ |
Easy |
HashMap |