10 |
Regular Expression Matching |
CPP |
Recursion |
Hard |
11 |
Container With Most Water |
CPP |
Trcik |
medium |
12 |
Interger to Roman |
CPP |
Trcik |
medium |
15 |
3Sum |
CPP |
Divide and Conquer |
medium |
16 |
3Sum Closest |
CPP |
Divide and Conquer |
medium |
18 |
4Sum |
CPP |
Divide and Conquer |
medium |
22 |
Generate Parentheses |
CPP |
Recursion |
medium |
23 |
Merge k Sorted Lists |
CPP |
Merge |
Hard |
25 |
Reverse Nodes in k-Group |
C++ |
Simulation |
Hard |
29 |
Divide Two Integers |
C++ |
Bit Operation |
Medium |
30 |
Substring with Concatenation of All Words |
C++ |
Data Structure |
Hard |
31 |
Next Permutation |
PY |
Trick |
Medium |
32 |
Longest Valid Parentheses |
C++ |
DP |
Hard |
33 |
Search in Rotated Sorted Array |
C++ |
Binary Search |
Medium |
34 |
Find First and Last Position of Element in Sorted Array |
C++ |
Binary Search |
Medium |
36 |
Valid Sudoku |
C++ |
Trick |
Medium |
37 |
Sudoku Solver |
C++ |
DFS |
Hard |
40 |
Combination Sum II |
C++ |
DP |
Medium |
41 |
First Missing Positive |
C++ |
Bucket+Trick |
Hard |
42 |
Trapping Rain Water |
C++ |
Data Structure |
Hard |
43 |
Multiply Strings |
C++ |
Trick |
Medium |
44 |
Wildcard Matching |
C++ |
Trick |
Hard |
45 |
Jump Game II |
C++ |
DP |
Hard |
46 |
Permutations |
C++ |
Trick |
Medium |
47 |
Permutations II |
C++ |
Trick+Data Structure |
Medium |
48 |
Rotate Image |
C++ |
Trick |
Medium |
49 |
Group Anagrams |
C++ |
Data Structure |
Medium |
50 |
Pow(x, n) |
C++ |
Quick Pow |
Medium |
51 |
N-Queens |
C++ |
DFS |
Hard |
52 |
N-Queens II |
C++ |
DFS |
Hard |
54 |
Spiral Matrix |
C++ |
Trick |
Medium |
56 |
Merge Intervals |
C++ |
Trick |
Medium |
57 |
Insert Interval |
C++ |
Trick |
Medium |
58 |
Length of Last Word |
C++ |
Trick |
Easy |
59 |
Spiral Matrix II |
C++ |
Trick |
Medium |
60 |
Permutation Sequence |
C++ |
DFS |
Hard |
61 |
Rotate List |
PY |
Trick |
Medium |
64 |
Minimum Path Sum |
C++ |
DP |
Medium |
65 |
Valid Number |
C++ |
STATE MACHINE |
Hard |
66 |
Plus One |
C++ |
Arbitrary-precision Arithmetic |
Easy |
67 |
Add Binary |
PY |
Arbitrary-precision Arithmetic |
Easy |
68 |
Text Justification |
C++ |
Trick |
Hard |
69 |
Sqrt(x) |
C++ |
Trick |
Easy |
71 |
Simplify Path |
C++ |
String Operations |
Medium |
72 |
Edit Distance |
C++ |
DP |
Hard |
73 |
Set Matrix Zeroes |
C++ |
Trick |
Medium |
74 |
Search a 2D Matrix |
C++ |
Binary Search |
Medium |
75 |
Sort Colors |
C++ |
Trick |
Medium |
76 |
Minimum Window Substring |
C++ |
Greedy |
Hard |
77 |
Combinations |
C++ |
DFS |
Medium |
79 |
Word Search |
C++ |
DFS |
Medium |
80 |
Remove Duplicates from Sorted Array II |
C++ |
Data Structure |
Medium |
81 |
Search in Rotated Sorted Array II |
C++ |
Binary Search |
Medium |
82 |
Remove Duplicates from Sorted List II |
C++ |
Linked List Operation |
Medium |
83 |
Remove Duplicates from Sorted List |
C++ |
Linked List Operation |
Easy |
84 |
Largest Rectangle in Histogram |
C++ |
Tricky |
Hard |
85 |
Maximal Rectangle |
SQL |
Tricky |
Hard |
86 |
Partition List |
C++ |
Linked List Operation |
Medium |
87 |
Scramble String |
C++ |
Recursion |
Hard |
88 |
Merge Sorted Array |
C++ |
Merge Sort |
Easy |
89 |
Gray Code |
C++ |
Bit Operation |
Medium |
90 |
Subsets II |
C++ |
DFS |
Medium |
91 |
Decode Ways |
C++ |
DP |
Medium |
92 |
Reverse Linked List II |
C++ |
Linked List Operation |
Medium |
93 |
Restore IP Addresses |
C++ |
Brute Force |
Medium |
94 |
Binary Tree Inorder Traversal |
C++ |
DFS |
Medium |
95 |
Unique Binary Search Trees II |
C++ |
DFS |
Medium |
97 |
Interleaving String |
C++ |
DP |
Hard |
98 |
Validate Binary Search Tree |
C++ |
DFS |
Medium |
99 |
Recover Binary Search Tree |
C++ |
DFS |
Hard |
101 |
Symmetric Tree |
C++ |
DFS |
Easy |
102 |
Binary Tree Level Order Traversal |
C++ |
DFS |
Medium |
103 |
Binary Tree Zigzag Level Order Traversal |
C++ |
DFS |
Medium |
104 |
Maximum Depth of Binary Tree |
C++ |
DFS |
Easy |
105 |
Construct Binary Tree from Preorder and Inorder Traversal |
C++ |
Recrusion |
Medium |
106 |
Construct Binary Tree from Inorder and Postorder Traversal |
C++ |
Recursion |
Medium |
107 |
Binary Tree Level Order Traversal II |
C++ |
DFS |
Medium |
108 |
Convert Sorted Array to Binary Search Tree |
C++ |
Recrusion |
Easy |
109 |
Convert Sorted List to Binary Search Tree |
C++ |
Recursion |
Medium |
110 |
Balanced Binary Tree |
C++ |
DFS |
Easy |
111 |
Minimum Depth of Binary Tree |
C++ |
DFS |
Easy |
112 |
Path Sum |
C++ |
DFS |
Easy |
113 |
Path Sum II |
C++ |
DFS |
Medium |
114 |
Flatten Binary Tree to Linked List |
C++ |
Recursion with While |
Medium |
115 |
Distinct Subsequences |
C++ |
DP |
Hard |
116 |
Populating Next Right Pointers in Each Node |
C++ |
Recursion |
Medium |
117 |
Populating Next Right Pointers in Each Node II |
C++ |
Recursion |
Medium |
118 |
Pascal's Triangle |
C++ |
DP |
Easy |
119 |
Pascal's Triangle II |
C++ |
DP |
Easy |
120 |
Triangle |
C++ |
DP |
Medium |
123 |
Best Time to Buy and Sell Stock III |
C++ |
DP |
Hard |
124 |
Binary Tree Maximum Path Sum |
C++ |
DFS |
Hard |
126 |
Word Ladder II |
C++ |
Memory Based Search |
Hard |
127 |
Word Ladder |
C++ |
Memory Based Search |
Hard |
128 |
Longest Consecutive Sequence |
C++ |
Brute Force with Data Structure |
Hard |
129 |
Sum Root to Leaf Numbers |
C++ |
DFS |
Medium |
130 |
Surrounded Regions |
C++ |
DFS |
Medium |
131 |
Palindrome Partitioning |
C++ |
Brute Force |
Medium |
132 |
Palindrome Partitioning II |
C++ |
DP |
Hard |
133 |
Clone Graph |
C++ |
Brute Force |
Medium |
135 |
Candy |
C++ |
DP |
Hard |
137 |
Single Number II |
C++ |
BIT OPERATION |
Medium |
138 |
Copy List with Random Pointer |
C++ |
Brute Force |
Medium |
139 |
Word Break |
PY |
DP |
Medium |
140 |
Word Break II |
PY |
DFS |
Hard |
141 |
Linked List Cycle |
C++ |
Tricky |
Easy |
142 |
Linked List Cycle II |
C++ |
Tricky |
Medium |
143 |
Reorder List |
C++ |
Simulation |
Medium |
144 |
Binary Tree Preorder Traversal |
C++ |
DFS |
Medium |
145 |
Binary Tree Postorder Traversal |
C++ |
DFS |
Medium |
146 |
LRU Cache |
C++ |
Data Structure |
Medium |
147 |
Insertion Sort List |
C++ |
Simulation |
Medium |
149 |
Max Points on a Line |
C++ |
Tricky |
Hard |
150 |
Evaluate Reverse Polish Notation |
C++ |
Data Structure |
Medium |
151 |
Reverse Words in a String |
PYs |
Simulation |
Medium |
152 |
Maximum Product Subarray |
C++ |
DP |
Medium |
153 |
Find Minimum in Rotated Sorted Array |
C++ |
Binary Search |
Medium |
154 |
Find Minimum in Rotated Sorted Array II |
C++ |
Binary Search |
Hard |
155 |
Min Stack |
C++ |
Data Structure |
Easy |
160 |
Intersection of Two Linked Lists |
C++ |
Linked List Operation |
Easy |
162 |
Find Peak Element |
C++ |
Binary Search |
Medium |
164 |
Maximum Gap |
C++ |
Tricky |
Hard |
165 |
Compare Version Numbers |
C++ |
Data Structure |
Medium |
166 |
Fraction to Recurring Decimal |
C++ |
Tricky |
Medium |
167 |
Two Sum II - Input array is sorted |
C++ |
Binary Search |
Easy |
168 |
Excel Sheet Column Title |
C++ |
Simulation |
Easy |
169 |
Majority Element |
C++ |
Tricky |
Easy |
171 |
Excel Sheet Column Number |
C++ |
Simulation |
Easy |
172 |
Factorial Trailing Zeroes |
C++ |
Tricky |
Easy |
173 |
Binary Search Tree Iterator |
C++ |
DFS |
Medium |
174 |
Dungeon Game |
C++ |
DP |
Hard |
175 |
Combine Two Tables |
SQL |
SQL |
Easy |
176 |
Second Highest Salary |
SQL |
SQL |
Easy |
177 |
Nth Highest Salary |
SQL |
SQL |
Medium |
178 |
Rank Scores |
SQL |
SQL |
Medium |
179 |
Largest Number |
C++ |
Recurssion |
Medium |
180 |
Consecutive Numbers |
SQL |
SQL |
Medium |
181 |
Employees Earning More Than Their Managers |
SQL |
SQL |
Easy |
182 |
Duplicate Emails |
SQL |
SQL |
Easy |
183 |
Customers Who Never Order |
SQL |
SQL |
Easy |
184 |
Department Highest Salary |
SQL |
SQL |
Medium |
185 |
Department Top Three Salaries |
SQL |
SQL |
Hard |
187 |
Repeated DNA Sequences |
C++ |
Data Structure |
Medium |
188 |
Best Time to Buy and Sell Stock IV |
C++ |
DP |
Hard |
189 |
Rotate Array |
C++ |
Simulation |
Medium |
190 |
Reverse Bits |
C++ |
Bit Operation |
Easy |
191 |
Number of 1 Bits |
C++ |
Bit Operations |
Easy |
192 |
Word Frequency |
SH |
Linux |
Medium |
193 |
Valid Phone Numbers |
SH |
Linux |
Easy |
194 |
Transpose File |
SH |
Linux |
Medium |
195 |
Tenth Line |
SH |
Linux |
Easy |
196 |
Delete Duplicate Emails |
SQL |
SQL |
Easy |
197 |
Rising Temperature |
SQL |
SQL |
Easy |
199 |
Binary Tree Right Side View |
C++ |
Tricky |
Medium |
200 |
Number of Islands |
C++ |
DFS |
Medium |
201 |
Bitwise AND of Numbers Range |
C++ |
Bit Operations |
Medium |
202 |
Happy Number |
C++ |
Simulation |
Easy |
203 |
Remove Linked List Elements |
C++ |
Linked List Operations |
Easy |
204 |
Count Primes |
C++ |
Tricky |
Easy |
205 |
Isomorphic Strings |
C++ |
Simulation |
Easy |
206 |
Reverse Linked List |
C++ |
Linked List Operations |
Easy |
207 |
Course Schedule |
C++ |
DFS |
Medium |
208 |
Implement Trie (Prefix Tree) |
C++ |
Data Structure |
Medium |
209 |
Minimum Size Subarray Sum |
C++ |
Tricky |
Medium |
210 |
Course Schedule II |
C++ |
Brute Force |
Medium |
212 |
Word Search II |
C++ |
Data Structure |
Hard |
214 |
Shortest Palindrome |
C++ |
Recursion |
Hard |
215 |
Kth Largest Element in an Array |
C++ |
Simulation |
Medium |
217 |
Contains Duplicate |
C++ |
Data Structure |
Easy |
218 |
The Skyline Problem |
C++ |
Simulation |
Hard |
219 |
Contains Duplicate II |
C++ |
Data Structure |
Easy |
221 |
Maximal Square |
C++ |
DP |
Medium |
222 |
Count Complete Tree Nodes |
C++ |
Recursion |
Medium |
223 |
Rectangle Area |
C++ |
Tricky |
Medium |
224 |
Basic Calculator |
PY |
Stack |
Hard |
225 |
Implement Stack using Queues |
C++ |
Data Structure |
Easy |
226 |
Invert Binary Tree |
C++ |
Recursion |
Easy |
227 |
Basic Calculator II |
C++ |
Stack |
Medium |
230 |
Kth Smallest Element in a BST |
C++ |
DFS |
Medium |
231 |
Power of Two |
C++ |
Simulation |
Easy |
232 |
Implement Queue using Stacks |
C++ |
Data Structure |
Easy |
233 |
Number of Digit One |
C++ |
Tricky |
Hard |
234 |
Palindrome Linked List |
C++ |
Linked List Operation |
Easy |
235 |
Lowest Common Ancestor of a Binary Search Tree |
C++ |
Recursion |
Easy |
236 |
Lowest Common Ancestor of a Binary Tree |
C++ |
Recursion |
Medium |
237 |
Delete Node in a Linked List |
C++ |
Linked List Operation |
Easy |
238 |
Product of Array Except Self |
C++ |
Tricky |
Medium |
239 |
Sliding Window Maximum |
C++ |
Tricky |
Hard |
240 |
Search a 2D Matrix II |
C++ |
Binary Search |
Medium |
241 |
Different Ways to Add Parentheses |
C++ |
DP+Recursion |
Medium |
242 |
Valid Anagram |
C++ |
Data Structure |
Easy |
257 |
Binary Tree Paths |
C++ |
Recursion |
Easy |
258 |
Add Digits |
C++ |
Simulation |
Easy |
260 |
Single Number III |
C++ |
Bit Operations |
Medium |
262 |
Trips and Users |
SQL |
SQL |
Hard |
263 |
Ugly Number |
C++ |
Simulation |
Easy |
264 |
Ugly Number II |
C++ |
Simulation |
Medium |
268 |
Missing Number |
C++ |
Tricky |
Easy |
273 |
Integer to English Words |
C++ |
Simulation |
Hard |
274 |
H-Index |
C++ |
Tricky |
Medium |
275 |
H-Index II |
C++ |
Tricky |
Medium |
278 |
First Bad Version |
C++ |
Binary Search |
Easy |
279 |
Perfect Squares |
PY |
DP |
Medium |
282 |
Expression Add Operators |
C++ |
DFS |
Hard |
283 |
Move Zeroes |
PY |
Simulation |
Easy |
284 |
Peeking Iterator |
C++ |
Simulation |
Medium |
287 |
Find the Duplicate Number |
C++ |
Tricky |
Medium |
289 |
Game of Life |
C++ |
Simulation |
Medium |
292 |
Nim Game |
C++ |
Tricky |
Easy |
301 |
Remove Invalid Parentheses |
C++ |
Brute Force |
Hard |
303 |
Range Sum Query - Immutable |
C++ |
Data Structure |
Easy |
304 |
Range Sum Query 2D - Immutable |
C++ |
Data Structure |
Medium |
306 |
Additive Number |
C++ |
Brute Force |
Medium |
307 |
Range Sum Query - Mutable |
C++ |
Data Structure |
Medium |
309 |
Best Time to Buy and Sell Stock with Cooldown |
C++ |
DP |
Medium |
312 |
Burst Balloons |
C++ |
DP |
Hard |
313 |
Super Ugly Number |
C++ |
DP |
Medium |
315 |
Count of Smaller Numbers After Self |
C++ |
Data Structure |
Hard |
318 |
Maximum Product of Word Lengths |
C++ |
Brute Force |
Medium |
319 |
Bulb Switcher |
C++ |
Trick |
Medium |
321 |
Create Maximum Number |
C++ |
Greedy+DP |
Hard |
324 |
Wiggle Sort II |
C++ |
Greedy+DP |
Medium |
327 |
Count of Range Sum |
C++ |
Data Structure |
Hard |
328 |
Odd Even Linked List |
C++ |
Data Structure |
Medium |
329 |
Longest Increasing Path in a Matrix |
C++ |
DP+DFS |
Hard |
330 |
Patching Array |
C++ |
Tricky |
Hard |
331 |
Verify Preorder Serialization of a Binary Tree |
C++ |
Tricky |
Medium |
332 |
Reconstruct Itinerary |
C++ |
DFS+Tricky |
Medium |
334 |
Increasing Triplet Subsequence |
C++ |
Tricky |
Medium |
335 |
Self Crossing |
C++ |
Tricky |
Hard |
336 |
Palindrome Pairs |
C++ |
Data Structure |
Hard |
341 |
Flatten Nested List Iterator |
C++ |
Data Structure |
Medium |
342 |
Power of Four |
C++ |
Math |
Easy |
343 |
Integer Break |
C++ |
Math |
Medium |
344 |
Reverse String |
C++ |
Data Structure |
Easy |
345 |
Reverse Vowels of a String |
C++ |
Simulation |
Easy |
347 |
Top K Frequent Elements |
C++ |
Data Structure |
Medium |
349 |
Intersection of Two Arrays |
C++ |
Data Structure |
Easy |
350 |
Intersection of Two Arrays II |
C++ |
Data Structure |
Easy |
352 |
Data Stream as Disjoint Intervals |
C++ |
Data Structure |
Hard |
355 |
Design Twitter |
C++ |
Data Structure |
Medium |
357 |
Count Numbers with Unique Digits |
C++ |
Trick |
Medium |
363 |
Max Sum of Rectangle No Larger Than K |
C++ |
Data Structure |
Hard |
365 |
Water and Jug Problem |
C++ |
Trick |
Medium |
367 |
Valid Perfect Square |
C++ |
Trick |
Easy |
368 |
Largest Divisible Subset |
C++ |
DP |
Medium |
371 |
Sum of Two Integers |
C++ |
Trick |
Medium |
372 |
Super Pow |
C++ |
Trick |
Medium |
373 |
Find K Pairs with Smallest Sums |
C++ |
Trick |
Medium |
374 |
Guess Number Higher or Lower |
C++ |
Binary Search |
Easy |
375 |
Guess Number Higher or Lower II |
C++ |
Binary Search |
Medium |
378 |
Kth Smallest Element in a Sorted Matrix |
C++ |
Binary Search |
Medium |
380 |
Insert Delete GetRandom O(1) |
C++ |
Data Structure |
Medium |
381 |
Insert Delete GetRandom O(1) - Duplicates allowed |
C++ |
Data Structure |
Hard |
383 |
Ransom Note |
PY |
String Operations |
Easy |
384 |
Shuffle an Array |
C++ |
Data Structure |
Medium |
385 |
Mini Parser |
C++ |
Recursion |
Medium |
386 |
Lexicographical Numbers |
C++ |
Trick |
Medium |
387 |
First Unique Character in a String |
C++ |
Data Structure |
Easy |
388 |
Longest Absolute File Path |
C++ |
Data Structure |
Medium |
390 |
Elimination Game |
C++ |
Data Structure |
Medium |
391 |
Perfect Rectangle |
C++ |
Bit Operation |
Hard |
392 |
Is Subsequence |
PY |
String Operations |
Easy |
393 |
UTF-8 Validation |
C++ |
Bit Operation |
Medium |
396 |
Rotate Function |
C++ |
Tricky |
Medium |
397 |
Integer Replacement |
C++ |
Tricky |
Medium |
398 |
Random Pick Index |
C++ |
Tricky |
Medium |
400 |
Nth Digit |
C++ |
Tricky |
Medium |
401 |
Binary Watch |
C++ |
Bit Operation |
Easy |
402 |
Remove K Digits |
C++ |
Data Structure |
Easy |
403 |
Frog Jump |
C++ |
DP |
Hard |
404 |
Sum of Left Leaves |
C++ |
Tree |
Easy |
405 |
Convert a Number to Hexadecimal |
C++ |
Tree |
Easy |
406 |
Queue Reconstruction by Height |
C++ |
Tree |
Medium |
407 |
Trapping Rain Water II |
C++ |
BFS |
Hard |
409 |
Longest Palindrome |
C++ |
Brute Force |
Easy |
410 |
Split Array Largest Sum |
C++ |
Binary Search |
Hard |
412 |
Fizz Buzz |
C++ |
Simulation |
Easy |
413 |
Arithmetic Slices |
C++ |
Tricky |
Medium |
414 |
Third Maximum Number |
C++ |
Simulation |
Easy |
416 |
Partition Equal Subset Sum |
C++ |
Data Structure |
Medium |
417 |
Pacific Atlantic Water Flow |
C++ |
Data Structure |
Medium |
419 |
Battleships in a Board |
C++ |
DFS |
Medium |
420 |
Strong Password Checker |
C++ |
Greedy |
Hard |
421 |
Maximum XOR of Two Numbers in an Array |
C++ |
Data Structure |
Medium |
423 |
Reconstruct Original Digits from English |
C++ |
Simulation |
Medium |
424 |
Longest Repeating Character Replacement |
C++ |
Binary Search |
Medium |
427 |
Construct Quad Tree |
C++ |
Recursion |
Medium |
429 |
N-ary Tree Level Order Traversal |
C++ |
DFS |
Medium |
430 |
Flatten a Multilevel Doubly Linked List |
C++ |
Recursion |
Medium |
432 |
All O`one Data Structure |
C++ |
Data Structure |
Hard |
433 |
Minimum Genetic Mutation |
C++ |
DFS |
Medium |
434 |
Number of Segments in a String |
PY |
String Operations |
Easy |
435 |
Non-overlapping Intervals |
CPP |
Greedy |
Medium |
436 |
Find Right Interval |
CPP |
Data Structure |
Medium |
437 |
Path Sum III |
CPP |
DFS |
Medium |
438 |
Find All Anagrams in a String |
CPP |
String Operations |
Medium |
440 |
K-th Smallest in Lexicographical Order |
CPP |
Tricky |
Hard |
441 |
Arranging Coins |
CPP |
Tricky |
Easy |
442 |
Find All Duplicates in an Array |
CPP |
Tricky |
Medium |
443 |
String Compression |
CPP |
String Operations |
Medium |
446 |
Arithmetic Slices II - Subsequence |
CPP |
DP / Tricky |
Hard |
447 |
Number of Boomerangs |
CPP |
Data Structure |
Medium |
448 |
Find All Numbers Disappeared in an Array |
CPP |
Tricky |
Easy |
450 |
Delete Node in a BST |
CPP |
Data Structure |
Medium |
451 |
Sort Characters By Frequency |
PY |
Data Structure |
Medium |
452 |
Minimum Number of Arrows to Burst Balloons |
CPP |
Tricky |
Medium |
453 |
Minimum Moves to Equal Array Elements |
PY |
Tricky |
Medium |
454 |
4Sum II |
CPP |
Data Structure |
Medium |
455 |
Assign Cookies |
CPP |
Greedy |
Easy |
456 |
132 Pattern |
CPP |
Stack |
Medium |
457 |
Circular Array Loop |
CPP |
Simulation |
Medium |
458 |
Poor Pigs |
CPP |
Mathematics |
HARD |
459 |
Repeated Substring Pattern |
PY |
String Operations |
Easy |
460 |
LFU Cache |
CPP |
Mathematics |
Hard |
461 |
Hamming Distance |
CPP |
Bit Operation |
Easy |
462 |
Minimum Moves to Equal Array Elements II |
PY |
Tricky |
Medium |
463 |
Island Perimeter |
PY |
Brute Force |
Easy |
464 |
Can I Win |
PY |
BFS |
Medium |
466 |
Count The Repetitions |
CPP |
Tricky+String Operations |
Hard |
467 |
Unique Substrings in Wraparound String |
CPP |
Tricky |
Medium |
468 |
Validate IP Address |
PY |
String Operations |
Medium |
470 |
Implement Rand10() Using Rand7() |
CPP |
Mathematics |
Medium |
472 |
Concatenated Words |
CPP |
Tricky+DP+String Operations |
Hard |
473 |
Matchsticks to Square |
CPP |
DP+Tricky+DFS |
Medium |
474 |
Ones and Zeroes |
CPP |
DP |
Medium |
475 |
Heaters |
CPP |
Binary Search |
Medium |
477 |
Total Hamming Distance |
CPP |
Bit Operations |
Medium |
478 |
Generate Random Point in a Circle |
CPP |
Mathematics |
Medium |
479 |
Largest Palindrome Product |
CPP |
Brute Force |
Hard |
480 |
Sliding Window Median |
CPP |
Data Structure |
Hard |
481 |
Magical String |
CPP |
Mathematics+String Operations |
Medium |
482 |
License Key Formatting |
PY |
String Operations |
Easy |
483 |
Smallest Good Base |
CPP |
Mathematics |
Hard |
485 |
Max Consecutive Ones |
CPP |
Tricky |
Easy |
486 |
Predict the Winner |
CPP |
DP |
Medium |
488 |
Zuma Game |
PY |
Brute Force |
Hard |
491 |
Increasing Subsequences |
PY |
Brute Force |
Medium |
492 |
Construct the Rectangle |
CPP |
Tricky |
Easy |
493 |
Reverse Pairs |
CPP |
Data Structure |
Hard |
494 |
Target Sum |
CPP |
Brute Force + DP |
Medium |
495 |
Teemo Attacking |
CPP |
Simulation |
Easy |
496 |
Next Greater Element I |
CPP |
Data Structure |
Easy |
497 |
Random Point in Non-overlapping Rectangles |
CPP |
Binary Search |
Medium |
498 |
Diagonal Traverse |
PY |
Tricky |
Medium |
500 |
Keyboard Row |
PY |
Tricky |
Easy |
501 |
Find Mode in Binary Search Tree |
PY |
Data Structure |
Easy |
502 |
IPO |
PY |
Greedy |
Hard |
503 |
Next Greater Element II |
PY |
Data Structure |
Medium |
504 |
Base 7 |
PY |
Tricky |
Easy |
506 |
Relative Ranks |
PY |
Data Structure |
Easy |
507 |
Perfect Number |
PY |
Tricky |
Easy |
508 |
Most Frequent Subtree Sum |
PY |
Data Structure |
Medium |
509 |
Most Frequent Subtree Sum |
PY |
Simulation |
Easy |
513 |
Find Bottom Left Tree Value |
PY |
Data Structure |
Medium |
514 |
Freedom Trail |
CPP |
DP |
Hard |
515 |
Find Largest Value in Each Tree Row |
PY |
Data Structure |
Medium |
516 |
Longest Palindromic Subsequence |
PY |
DP |
Medium |
517 |
Super Washing Machines |
PY |
Greedy |
Hard |
518 |
Coin Change 2 |
CPP |
DP |
Medium |
519 |
Random Flip Matrix |
CPP |
Tricky |
Medium |
520 |
Detect Capital |
GO |
Simulation |
Easy |
521 |
Longest Uncommon Subsequence I |
GO |
Simulation |
Easy |
522 |
Longest Uncommon Subsequence II |
GO |
Greedy |
Medium |
523 |
Continuous Subarray Sum |
GO |
Data Structure |
Medium |
524 |
Longest Word in Dictionary through Deleting |
GO |
String Operations |
Medium |
526 |
Beautiful Arrangement |
GO |
Brute Force |
Medium |
528 |
Random Pick with Weight |
C++ |
Binary Search |
Medium |
529 |
Minesweeper |
GO |
Simulation |
Medium |
530 |
Minimum Absolute Difference in BST |
GO |
Simulation |
Easy |
532 |
K-diff Pairs in an Array |
GO |
Simulation |
Medium |
535 |
Encode and Decode TinyURL |
GO |
String Operation |
Medium |
538 |
Convert BST to Greater Tree |
GO |
DFS |
Medium |
539 |
Minimum Time Difference |
GO |
Tricky |
Medium |
540 |
Single Element in a Sorted Array |
CPP |
Binary Search |
Medium |
541 |
Reverse String II |
GO |
String Operation |
Easy |
542 |
01 Matrix |
GO |
DP |
Medium |
546 |
Remove Boxes |
CPP |
DP |
Hard |
547 |
Number of Provinces |
GO |
Brute Force |
Medium |
551 |
Student Attendance Record I |
GO |
Brute Force |
Easy |
552 |
Student Attendance Record II |
C++ |
Mathematics |
Hard |
553 |
Optimal Division |
GO |
Tricky |
Medium |
554 |
Brick Wall |
GO |
Dynamic Programming |
Medium |
556 |
Next Greater Element III |
GO |
Data Structure |
Medium |
557 |
Reverse Words in a String III |
PY |
String Operations |
Easy |
558 |
Logical OR of Two Binary Grids Represented as Quad-Trees |
PY |
Recursion |
Medium |
559 |
Maximum Depth of N-ary Tree |
PY |
Recursion |
Easy |
560 |
Subarray Sum Equals K |
PY |
Data Structure |
Medium |
561 |
Array Partition |
PY |
Greedy |
Easy |
563 |
Binary Tree Tilt |
PY |
Recursion |
Easy |
564 |
Find the Closest Palindrome |
PY |
Tricky |
Hard |
566 |
Reshape the Matrix |
PY |
Tricky |
Easy |
567 |
Permutation in String |
C++ |
Data Structure |
Medium |
572 |
Subtree of Another Tree |
GO |
Data Structure |
Easy |
575 |
Distribute Candies |
GO |
Simulation |
Easy |
576 |
Out of Boundary Paths |
GO |
Memory Based Search |
Medium |
581 |
Shortest Unsorted Continuous Subarray |
GO |
Tricky |
Medium |
583 |
Delete Operation for Two Strings |
GO |
Dynamic Programming |
Medium |
584 |
Find Customer Referee |
SQL |
Tricky |
Easy |
586 |
Customer Placing the Largest Number of Orders |
SQL |
Tricky |
Easy |
587 |
Erect the Fence |
GO |
Computing Geometry |
Hard |
590 |
N-ary Tree Postorder Traversal |
GO |
DFS |
Easy |
591 |
Tag Validator |
PY |
State Machine |
Hard |
592 |
Fraction Addition and Subtraction |
PY |
Mathematics |
Medium |
594 |
Longest Harmonious Subsequence |
GO |
Mathematics |
Easy |
595 |
Big Countries |
SQL |
Tricky |
Easy |
596 |
Classes More Than 5 Students |
SQL |
Trikcy |
Easy |
599 |
Minimum Index Sum of Two Lists |
GO |
Data Structure |
Easy |
600 |
Non-negative Integers without Consecutive Ones |
GO |
Mathematics |
Hard |
601 |
Human Traffic of Stadium |
SQL |
Tricky |
Hard |
602 |
Friend Requests II: Who Has the Most Friends |
SQL |
Tricky |
Medium |
605 |
Can Place Flowers |
GO |
Greedy |
Easy |
606 |
Construct String from Binary Tree |
GO |
String Operations |
Easy |
607 |
Sales Person |
SQL |
Tricky |
Easy |
608 |
Tree Node |
SQL |
Tricky |
Easy |
610 |
Triangle Judgement |
SQL |
Tricky |
Easy |
611 |
Valid Triangle Number |
GO |
Tricky |
Medium |
617 |
Merge Two Binary Trees |
GO |
Tricky |
Easy |
619 |
Biggest Single Number |
SQL |
Tricky |
Easy |
621 |
Task Scheduler |
GO |
Tricky |
Medium |
622 |
Design Circular Queue |
GO |
Tricky |
Medium |
623 |
Add One Row to Tree |
GO |
Tricky |
Medium |
626 |
Exchange Seats |
SQL |
Tricky |
Medium |
627 |
Swap Salary |
SQL |
Tricky |
Easy |
628 |
Maximum Product of Three Numbers |
GO |
Tricky |
Easy |
630 |
Course Schedule III |
GO |
Data Structure |
Hard |
632 |
Smallest Range Covering Elements from K Lists |
GO |
Tricky + Data Structure |
Hard |
636 |
Exclusive Time of Functions |
GO |
Tricky +Stack |
Medium |
637 |
Average of Levels in Binary Tree |
GO |
Data Structure |
Easy |
638 |
Shopping Offers |
PY |
DFS |
Medium |