| 0001 |
Two Sum |
Solution |
Easy |
|
| 0002 |
Add Two Numbers |
Solution |
Medium |
|
| 0003 |
Longest Substring Without Repeating Characters |
Solution |
Medium |
|
| 0004 |
Median of Two Sorted Arrays |
Solution |
Hard |
|
| 0005 |
Longest Palindromic Substring |
Solution |
Medium |
To Optimize |
| 0006 |
ZigZag Conversion |
Solution |
Medium |
|
| 0007 |
Reverse Integer |
Solution |
Easy |
|
| 0008 |
String to Integer (atoi) |
Solution |
Medium |
Not Recommend |
| 0009 |
Palindrome Number |
Solution |
Easy |
|
| 0011 |
Container With Most Water |
Solution |
Medium |
|
| 0013 |
Roman to Integer |
Solution |
Easy |
Not Recommend |
| 0014 |
Longest Common Prefix |
Solution |
Easy |
|
| 0015 |
3Sum |
Solution |
Medium |
|
| 0016 |
3Sum Closest |
Solution |
Medium |
|
| 0017 |
Letter Combinations of a Phone Number |
Solution |
Medium |
|
| 0018 |
4Sum |
Solution |
Medium |
|
| 0019 |
Remove Nth Node From End of List |
Solution |
Medium |
Double-Pointer |
| 0020 |
Valid Parentheses |
Solution |
Easy |
|
| 0021 |
Merge Two Sorted Lists |
Solution |
Easy |
|
| 0026 |
Remove Duplicates from Sorted Array |
Solution |
Easy |
|
| 0027 |
Remove Element |
Solution |
Easy |
|
| 0035 |
Search Insert Position |
Solution |
Easy |
|
| 0039 |
Combination Sum |
Solution |
Medium |
Backtracing |
| 0040 |
Combination Sum II |
Solution |
Medium |
Backtracing |
| 0046 |
Permutations |
Solution |
Medium |
|
| 0047 |
Permutations |
Solution |
Medium |
Backtracing |
| 0049 |
Group Anagrams |
Solution |
Medium |
|
| 0051 |
N-Queens |
Solution |
Hard |
BackTracing |
| 0052 |
N-Queens II |
Solution |
Hard |
BackTracing |
| 0053 |
Maximum Subarray |
Solution |
Easy |
DP |
| 0062 |
Unique Paths |
Solution |
Medium |
|
| 0063 |
Unique Paths II |
Solution |
Medium |
|
| 0064 |
Minimum Path Sum |
Solution |
Medium |
|
| 0066 |
Plus One |
Solution |
Easy |
|
| 0070 |
Climbing Stairs |
Solution |
Easy |
|
| 0075 |
Sort Colors |
Solution |
Medium |
|
| 0076 |
Minimum Window Substring |
Solution |
Hard |
|
| 0080 |
Remove Duplicates from Sorted Array II |
Solution |
Medium |
|
| 0088 |
Merge Sorted Array |
Solution |
Easy |
|
| 0091 |
Decode Ways |
Solution |
Medium |
|
| 0093 |
Restore IP Addresses |
Solution |
Medium |
|
| 0096 |
Unique Binary Search Trees |
Solution |
Medium |
|
| 0104 |
Maximum Depth of Binary Tree |
Solution |
Easy |
Recursion |
| 0120 |
Triangle |
Solution |
Medium |
|
| 0121 |
Best Time to Buy and Sell Stock |
Solution |
Easy |
DP |
| 0122 |
Best Time to Buy and Sell Stock II |
Solution |
Easy |
DP |
| 0123 |
Best Time to Buy and Sell Stock III |
Solution |
Hard |
DP |
| 0125 |
Valid Palindrome |
Solution |
Medium |
|
| 0131 |
Palindrome Partitioning |
Solution |
Medium |
|
| 0149 |
Max Points on a Line |
Solution |
Hard |
|
| 0167 |
Two Sum II - Input array is sorted |
Solution |
Easy |
|
| 0188 |
Best Time to Buy and Sell Stock IV |
Solution |
Hard |
DP |
| 0198 |
House Robber |
Solution |
Easy |
|
| 0199 |
Binary Tree Right Side View |
Solution |
Medium |
BackTracing |
| 0202 |
Happy Number |
Solution |
Easy |
|
| 0203 |
Remove Linked List Elements |
Solution |
Easy |
|
| 0205 |
Isomorphic Strings |
Solution |
Easy |
|
| 0206 |
Reverse Linked List |
Solution |
Easy |
|
| 0208 |
Implement Trie (Prefix Tree) |
Solution |
Medium |
|
| 0209 |
Minimum Size Subarray Sum |
Solution |
Medium |
|
| 0211 |
Add and Search Word - Data structure design |
Solution |
Medium |
|
| 0213 |
House Robber II |
Solution |
Medium |
|
| 0215 |
Kth Largest Element in an Array |
Solution |
Medium |
|
| 0216 |
Combination Sum III |
Solution |
Medium |
Backtracing |
| 0217 |
Contains Duplicate |
Solution |
Easy |
|
| 0219 |
Contains Duplicate II |
Solution |
Easy |
|
| 0220 |
Contains Duplicate III |
Solution |
Medium |
|
| 0242 |
Valid Anagram |
Solution |
Easy |
|
| 0279 |
Valid Anagram |
Solution |
Medium |
|
| 0283 |
Move Zeroes |
Solution |
Easy |
|
| 0290 |
Word Pattern |
Solution |
Easy |
|
| 0300 |
Longest Increasing Subsequence |
Solution |
Medium |
|
| 0303 |
Range Sum Query - Immutable |
Solution |
Easy |
|
| 0307 |
Range Sum Query - Mutable |
Solution |
Medium |
|
| 0309 |
Best Time to Buy and Sell Stock with Cooldown |
Solution |
Medium |
DP |
| 0332 |
Reconstruct Itinerary |
Solution |
Medium |
Graph |
| 0338 |
Counting Bits |
Solution |
Medium |
|
| 0343 |
Integer Break |
Solution |
Medium |
|
| 0344 |
Reverse String |
Solution |
Easy |
|
| 0345 |
Reverse Vowels of a String |
Solution |
Easy |
|
| 0347 |
Top K Frequent Elements |
Solution |
Medium |
|
| 0349 |
Intersection of Two Arrays |
Solution |
Easy |
|
| 0350 |
Intersection of Two Arrays II |
Solution |
Easy |
|
| 0376 |
Wiggle Subsequence |
Solution |
Medium |
|
| 0438 |
Find All Anagrams in a String |
Solution |
Medium |
|
| 0447 |
Number of Boomerangs |
Solution |
Easy |
|
| 0454 |
4Sum II |
Solution |
Medium |
|
| 0530 |
Minimum Absolute Difference in BST |
Solution |
Easy |
|
| 0557 |
Reverse Words in a String III |
Solution |
Easy |
|
| 0606 |
Construct String from Binary Tree |
Solution |
Easy |
|
| 0677 |
Map Sum Pairs |
Solution |
Medium |
|
| 0700 |
Search in a Binary Search Tree |
Solution |
Easy |
|
| 0783 |
Minimum Distance Between BST Nodes |
Solution |
Easy |
|
| 0804 |
Unique Morse Code Words |
Solution |
Easy |
|
| 0877 |
Stone Game |
Solution |
Medium |
|
| 0938 |
Range Sum of BST |
Solution |
Easy |
|
| 1025 |
Divisor Game |
Solution |
Easy |
|
