| 0001 |
Two Sum |
Python |
Easy |
Blind75, Grind75, Array |
| 0002 |
Add Two Numbers |
Python |
Medium |
|
| 0003 |
Longest Substring Without Repeating Characters |
Python |
Medium |
Blind75, Grind75, String |
| 0005 |
Longest Palindromic Substring |
Python |
Medium |
Blind75, Grind75, String |
| 0006 |
Zigzag Conversion |
Python |
Medium |
|
| 0007 |
Reverse Integer |
Python |
Medium |
|
| 0008 |
String to Integer (atoi) |
Python |
Medium |
Grind75, String |
| 0011 |
Container With Most Water |
Python |
Medium |
Blind75, Grind75, Array |
| 0012 |
Integer to Roman |
Python |
Medium |
|
| 0013 |
Roman to Integer |
Python |
Easy |
|
| 0014 |
Longest Common Prefix |
Python |
Easy |
|
| 0015 |
3Sum |
Python |
Medium |
Blind75, Grind75, Array |
| 0017 |
Letter Combinations of a Phone Number |
Python |
Medium |
Grind75, Recursion |
| 0019 |
Remove Nth Node From End of List |
Python |
Medium |
Blind75, Linked List |
| 0020 |
Valid Parentheses |
Python |
Easy |
Blind75, Grind75, String, Stack |
| 0021 |
Merge Two Sorted Lists |
Python |
Easy |
Blind75, Grind75, Linked List |
| 0022 |
Generate Parentheses |
Python |
Medium |
|
| 0024 |
Swap Nodes in Pairs |
Python |
Medium |
|
| 0026 |
Remove Duplicates from Sorted Array |
Python |
Easy |
|
| 0027 |
Remove Element |
Python |
Easy |
|
| 0028 |
Find the Index of the First Occurrence in a String |
Python |
Easy |
|
| 0033 |
Search in Rotated Sorted Array |
Python |
Medium |
Blind75, Grind75, Array, Binary Search |
| 0034 |
Find First and Last Position of Element in Sorted Array |
Python |
Medium |
Binary Search |
| 0035 |
Search Insert Position |
Python |
Easy |
|
| 0036 |
Valid Sudoku |
Python |
Medium |
|
| 0038 |
Count and Say |
Python |
Medium |
|
| 0039 |
Combination Sum |
Python |
Medium |
Blind75,Grind75, Array, Dynamic Programming |
| 0042 |
Trapping Rain Water |
Python |
Hard |
Grind75, Stack |
| 0043 |
Multiply Strings |
Python |
Medium |
|
| 0046 |
Permutations |
Python |
Medium |
Grind75, Recursion |
| 0047 |
Permutations II |
Python |
Medium |
|
| 0048 |
Rotate Image |
Python |
Medium |
Blind75, Matrix |
| 0049 |
Group Anagrams |
Python |
Medium |
Blind75, String |
| 0053 |
Maximum Subarray |
Python |
Medium |
Blind75, Grind75, Array |
| 0054 |
Spiral Matrix |
Python |
Medium |
Blind75, Grind75, Matrix |
| 0055 |
Jump Game |
Python |
Medium |
Blind75, Dynamic Programming |
| 0056 |
Merge Intervals |
Python |
Medium |
Blind75, Grind75, Interval, Sorting, Array |
| 0057 |
Insert Interval |
Python |
Medium |
Blind75, Grind75, Interval |
| 0058 |
Length of Last Word |
Python |
Easy |
|
| 0061 |
Rotate List |
Python |
Medium |
|
| 0062 |
Unique Paths |
Python |
Medium |
Blind75, Grind75, Dynamic Programming |
| 0067 |
Add Binary |
Python |
Easy |
Grind75, Binary |
| 0070 |
Climbing Stairs |
Python |
Easy |
|
| 0071 |
Simplify Path |
Python |
Medium |
|
| 0073 |
Set Matrix Zeroes |
Python |
Medium |
Blind75, Matrix |
| 0074 |
Search a 2D Matrix |
Python |
Medium |
|
| 0075 |
Sort Colors |
Python |
Medium |
Grind75, Array |
| 0076 |
Minimum Window Substring |
Python |
Hard |
Blind75, Grind75, String |
| 0078 |
Subsets |
Python |
Medium |
Grind75, Recursion |
| 0079 |
Word Search |
Python |
Medium |
Blind75, Grind75, Matrix, Graph |
| 0082 |
Remove Duplicates from Sorted List II |
Python |
Medium |
|
| 0083 |
Remove Duplicates from Sorted List |
Python |
Easy |
|
| 0084 |
Largest Rectangle in Histogram |
Python |
Hard |
|
| 0086 |
Partition List |
Python |
Medium |
|
| 0088 |
Merge Sorted Array |
Python |
Easy |
|
| 0091 |
Decode Ways |
Python |
Medium |
Blind75, Dynamic Programming |
| 0092 |
Reverse Linked List II |
Python |
Medium |
|
| 0094 |
Binary Tree Inorder Traversal |
Python |
Easy |
|
| 0096 |
Unique Binary Search Trees |
Python |
Medium |
|
| 0097 |
Interleaving String |
Python |
Medium |
Dynamic Programming |
| 0098 |
Validate Binary Search Tree |
Python |
Medium |
Blind75, Grind75, Tree |
| 0102 |
Binary Tree Level Order Traversal |
Python |
Medium |
Blind75, Grind75, BinaryTree |
| 0105 |
Construct Binary Tree from Preorder and Inorder Traversal |
Python |
Medium |
Blind75, BinaryTree |
| 0110 |
Balanced Binary Tree |
Python |
Easy |
Grind75, Binary Tree |
| 0112 |
Path Sum |
Python |
Easy |
|
| 0120 |
Triangle |
Python |
Medium |
Dynamic Programming |
| 0121 |
Best Time to Buy and Sell Stock |
Python |
Easy |
Blind75, Grind75, Array |
| 0125 |
Valid Palindrome |
Python |
Easy |
Blind75, Grind75, String |
| 0131 |
Palindrome Partitioning |
Python |
Medium |
|
| 0133 |
Clone Graph |
Python |
Medium |
Blind75, Grind75, Graph |
| 0136 |
Single Number |
Python |
Easy |
|
| 0138 |
Copy List with Random Pointer |
Python |
Medium |
Linked List |
| 0139 |
Word Break |
Python |
Medium |
Grind75, Linked List, Tree |
| 0141 |
Linked List Cycle |
Python |
Easy |
Grind75, Linked List |
| 0142 |
Linked List Cycle II |
Python |
Medium |
|
| 0146 |
LRU Cache |
Python |
Medium |
Grind75, Linked List |
| 0148 |
Sort List |
Python |
Medium |
|
| 0150 |
Evaluate Reverse Polish Notation |
Python |
Medium |
Grind75, Stack |
| 0152 |
Maximum Product Subarray |
Python |
Medium |
Blind75, Array |
| 0153 |
Find Minimum in Rotated Sorted Array |
Python |
Medium |
Blind75, Array |
| 0155 |
Min Stack |
Python |
Medium |
Grind75, Stack |
| 0160 |
Intersection of Two Linked Lists |
Python |
Easy |
|
| 0167 |
Two Sum II - Input Array Is Sorted |
Python |
Medium |
|
| 0169 |
Majority Element |
Python |
Easy |
Grind75, Array |
| 0189 |
Rotate Array |
Python |
Medium |
|
| 0191 |
Number of 1 Bits |
Python |
Easy |
Blind75, Binary |
| 0198 |
House Robber |
Python |
Medium |
Blind75, Dynamic Programming |
| 0200 |
Number of Islands |
Python |
Medium |
Blind75, Grind75, Graph |
| 0202 |
Happy Number |
Python |
Easy |
|
| 0203 |
Remove Linked List Elements |
Python |
Easy |
|
| 0205 |
Isomorphic Strings |
Python |
Easy |
|
| 0206 |
Reverse Linked List |
Python |
Easy |
Grind75, Linked List |
| 0207 |
Course Schedule |
Python |
Medium |
Blind75, Grind75, Graph |
| 0208 |
Implement Trie (Prefix Tree) |
Python |
Medium |
Blind75, Grind75, Tree |
| 0210 |
Course Schedule II |
Python |
Medium |
|
| 0213 |
House Robber II |
Python |
Medium |
Blind75, Dynamic Programming |
| 0215 |
Kth Largest Element in an Array |
Python |
Medium |
Quick Select |
| 0217 |
Contains Duplicate |
Python |
Easy |
Blind75, Grind75, Array |
| 0221 |
Maximal Square |
Python |
Medium |
Top Down Memoization |
| 0224 |
Basic Calculator |
Python |
Hard |
Grind75, Stack |
| 0225 |
Implement Stack using Queues |
Python |
Easy |
|
| 0226 |
Invert Binary Tree |
Python |
Easy |
Grind75, Binary Tree |
| 0227 |
Basic Calculator II |
Python |
Medium |
|
| 0228 |
Summary Ranges |
Python |
Easy |
|
| 0229 |
Majority Element II |
Python |
Medium |
|
| 0230 |
Kth Smallest Element in a BST |
Python |
Medium |
Blind75, Grind75, Binary Search Tree |
| 0232 |
Implement Queue using Stacks |
Python |
Easy |
Grind75, Stack |
| 0234 |
Palindrome Linked List |
Python |
Easy |
|
| 0235 |
Lowest Common Ancestor of a Binary Search Tree |
Python |
Medium |
Grind75, Binary Search Tree |
| 0238 |
Product of Array Except Self |
Python |
Medium |
Blind75, Grind75, Array |
| 0242 |
Valid Anagram |
Python |
Easy |
Blind75, Grind75, String |
| 0253 |
Meeting Rooms II |
Python |
Medium |
Blind75, Interval |
| 0261 |
Graph Valid Tree |
Python |
Medium |
Blind75, Graph |
| 0263 |
Ugly Number |
Python |
Easy |
|
| 0279 |
Perfect Squares |
Python |
Medium |
Dynamic Programming |
| 0283 |
Move Zeroes |
Python |
Easy |
|
| 0287 |
Find the Duplicate Number |
Python |
Medium |
Floyd's Cycle Detection |
| 0290 |
Word Pattern |
Python |
Easy |
|
| 0300 |
Longest Increasing Subsequence |
Python |
Medium |
Blind75, Dynamic Programming |
| 0316 |
Remove Duplicate Letters |
Python |
Medium |
|
| 0322 |
Coin Change |
Python |
Medium |
Blind75, Grind75, Dynamic Programming |
| 0323 |
Number of Connected Components in an Undirected Graph |
Python |
Medium |
Blind75, Graph, Union Find |
| 0328 |
Odd Even Linked List |
Python |
Medium |
|
| 0338 |
Counting Bits |
Python |
Easy |
Blind75, Binary |
| 0341 |
Flatten Nested List Iterator |
Python |
Medium |
|
| 0344 |
Reverse String |
Python |
Easy |
|
| 0347 |
Top K Frequent Elements |
Python |
Medium |
Blind75, Heap, Bucket Sort |
| 0349 |
Intersection of Two Arrays |
Python |
Easy |
|
| 0350 |
Intersection of Two Arrays II |
Python |
Easy |
|
| 0367 |
Valid Perfect Square |
Python |
Easy |
|
| 0374 |
Guess Number Higher or Lower |
Python |
Easy |
|
| 0383 |
Ransom Note |
Python |
Easy |
Grind75, Hash Table |
| 0385 |
Mini Parser |
Python |
Medium |
|
| 0387 |
First Unique Character in a String |
Python |
Easy |
|
| 0394 |
Decode String |
Python |
Medium |
|
| 0401 |
Binary Watch |
Python |
Easy |
|
| 0402 |
Remove K Digits |
Python |
Medium |
|
| 0409 |
Longest Palindrome |
Python |
Easy |
Grind75, String |
| 0416 |
Partition Equal Subset Sum |
Python |
Medium |
Grind75, Dynamic Programming |
| 0417 |
Pacific Atlantic Water Flow |
Python |
Medium |
Blind75, Graph |
| 0419 |
Battleships in a Board |
Python |
Medium |
|
| 0424 |
Longest Repeating Character Replacement |
Python |
Medium |
Blind75, String |
| 0430 |
Flatten a Multilevel Doubly Linked List |
Python |
Medium |
|
| 0438 |
Find All Anagrams in a String |
Python |
Medium |
Grind75, String |
| 0441 |
Arranging Coins |
Python |
Easy |
|
| 0442 |
Find All Duplicates in an Array |
Python |
Medium |
|
| 0448 |
Find All Numbers Disappeared in an Array |
Python |
Easy |
|
| 0456 |
132 Pattern |
Python |
Medium |
|
| 0459 |
Repeated Substring Pattern |
Python |
Easy |
|
| 0485 |
Max Consecutive Ones |
Python |
Easy |
|
| 0496 |
Next Greater Element I |
Python |
Easy |
|
| 0503 |
Next Greater Element II |
Python |
Medium |
|
| 0543 |
Diameter of Binary Tree |
Python |
Medium |
Grind75, Binary Tree |
| 0557 |
Reverse Words in a String III |
Python |
Easy |
|
| 0560 |
Subarray Sum Equals K |
Python |
Medium |
Prefix Sums |
| 0566 |
Reshape the Matrix |
Python |
Easy |
|
| 0572 |
Subtree of Another Tree |
Python |
Easy |
Blind75, Tree |
| 0575 |
Distribute Candies |
Python |
Easy |
|
| 0594 |
Longest Harmonious Subsequence |
Python |
Easy |
|
| 0599 |
Minimum Index Sum of Two Lists |
Python |
Easy |
|
| 0605 |
Can Place Flowers |
Python |
Easy |
|
| 0606 |
Construct String from Binary Tree |
Python |
Easy |
|
| 0617 |
Merge Two Binary Trees |
Python |
Easy |
|
| 0622 |
Design Circular Queue |
Python |
Medium |
|
| 0647 |
Palindromic Substrings |
Python |
Medium |
Blind75, String |
| 0657 |
Robot Return to Origin |
Python |
Easy |
|
| 0667 |
Beautiful Arrangement II |
Python |
Medium |
|
| 0680 |
Valid Palindrome II |
Python |
Easy |
|
| 0682 |
Baseball Game |
Python |
Easy |
|
| 0696 |
Count Binary Substrings |
Python |
Easy |
|
| 0703 |
Kth Largest Element in a Stream |
Python |
Easy |
|
| 0704 |
Binary Search |
Python |
Easy |
Grind75, Binary Search |
| 0705 |
Design HashSet |
Python |
Easy |
|
| 0706 |
Design HashMap |
Python |
Easy |
|
| 0707 |
Design Linked List |
Python |
Medium |
|
| 0724 |
Find Pivot Index |
Python |
Easy |
|
| 0733 |
Flood Fill |
Python |
Easy |
Grind75, Graph |
| 0739 |
Daily Temperatures |
Python |
Medium |
|
| 0746 |
Min Cost Climbing Stairs |
Python |
Easy |
Blind75, Grind75, Dynamic Programming |
| 0766 |
Toeplitz Matrix |
Python |
Easy |
|
| 0771 |
Jewels and Stones |
Python |
Easy |
|
| 0795 |
Number of Subarrays with Bounded Maximum |
Python |
Medium |
|
| 0816 |
Ambiguous Coordinates |
Python |
Medium |
|
| 0844 |
Backspace String Compare |
Python |
Easy |
|
| 0845 |
Longest Mountain in Array |
Python |
Medium |
|
| 0876 |
Middle of the Linked List |
Python |
Easy |
Grind75, Linked List |
| 0880 |
Decoded String at Index |
Python |
Medium |
|
| 0918 |
Maximum Sum Circular Subarray |
Python |
Medium |
|
| 0929 |
Unique Email Addresses |
Python |
Easy |
|
| 0949 |
Largest Time for Given Digits |
Python |
Medium |
|
| 0953 |
Verifying an Alien Dictionary |
Python |
Easy |
|
| 0977 |
Squares of a Sorted Array |
Python |
Easy |
|
| 1041 |
Robot Bounded In Circle |
Python |
Medium |
Math & Geometry |
| 1046 |
Last Stone Weight |
Python |
Easy |
|
| 1047 |
Remove All Adjacent Duplicates In String |
Python |
Easy |
|
| 1143 |
Longest Common Subsequence |
Python |
Medium |
Blind75, Dynamic Programming |
| 1189 |
Maximum Number of Balloons |
Python |
Easy |
|
| 1260 |
Shift 2D Grid |
Python |
Easy |
|
| 1299 |
Replace Elements with Greatest Element on Right Side |
Python |
Easy |
|
| 1332 |
Remove Palindromic Subsequences |
Python |
Easy |
|
| 1375 |
Number of Times Binary String Is Prefix-Aligned |
Python |
Medium |
|
| 1380 |
Lucky Numbers in a Matrix |
Python |
Easy |
|
| 1408 |
String Matching in an Array |
Python |
Easy |
|
| 1436 |
Destination City |
Python |
Easy |
|
| 1448 |
Count Good Nodes in Binary Tree |
Python |
Medium |
|
| 1466 |
Reorder Routes to Make All Paths Lead to the City Zero |
Python |
Medium |
|
| 1502 |
Can Make Arithmetic Progression From Sequence |
Python |
Easy |
|
| 1566 |
Detect Pattern of Length M Repeated K or More Times |
Python |
Easy |
|
| 1576 |
Replace All ?'s to Avoid Consecutive Repeating Characters |
Python |
Easy |
|
| 1588 |
Sum of All Odd Length Subarrays |
Python |
Easy |
|
| 1638 |
Count Substrings That Differ by One Character |
Python |
Medium |
|
| 1704 |
Determine if String Halves Are Alike |
Python |
Easy |
|
| 1721 |
Swapping Nodes in a Linked List |
Python |
Medium |
|
| 1748 |
Sum of Unique Elements |
Python |
Easy |
|
| 1758 |
Minimum Changes To Make Alternating Binary String |
Python |
Easy |
|
| 1763 |
Longest Nice Substring |
Python |
Easy |
|
| 1773 |
Count Items Matching a Rule |
Python |
Easy |
|
| 1779 |
Find Nearest Point That Has the Same X or Y Coordinate |
Python |
Easy |
|
| 1784 |
Check if Binary String Has at Most One Segment of Ones |
Python |
Easy |
|
| 1790 |
Check if One String Swap Can Make Strings Equal |
Python |
Easy |
|
| 1796 |
Second Largest Digit in a String |
Python |
Easy |
|
| 1805 |
Number of Different Integers in a String |
Python |
Easy |
|
| 1812 |
Determine Color of a Chessboard Square |
Python |
Easy |
|
| 1816 |
Truncate Sentence |
Python |
Easy |
|
| 1822 |
Sign of the Product of an Array |
Python |
Easy |
|
| 1832 |
Check if the Sentence Is Pangram |
Python |
Easy |
|
| 1844 |
Replace All Digits with Characters |
Python |
Easy |
|
| 1869 |
Longer Contiguous Segments of Ones than Zeros |
Python |
Easy |
|
| 1880 |
Check if Word Equals Summation of Two Words |
Python |
Easy |
|
| 1886 |
Determine Whether Matrix Can Be Obtained By Rotation |
Python |
Easy |
|
| 1888 |
Minimum Number of Flips to Make the Binary String Alternating |
Python |
Medium |
Sliding Window |
| 1911 |
Maximum Alternating Subsequence Sum |
Python |
Medium |
Dynamic Programming |
| 1963 |
Minimum Number of Swaps to Make the String Balanced |
Python |
Medium |
|
| 2028 |
Find Missing Observations |
Python |
Medium |
|