| 001 |
Two Sum |
Array HashTable |
| 007 |
Reverse Integer |
String |
| 008 |
String to Integer |
String Array |
| 014 |
Longest Common Prefix |
String Array |
| 019 |
Remove Nth Node From End of List |
LinkedList |
| 020 |
Valid Parentheses |
Stack |
| 021 |
Merge Two Sorted Lists |
LinkedList |
| 026 |
Remove Duplicates from Sorted Array |
Array |
| 028 |
Implement strStr |
String Array |
| 035 |
Search Insert Position |
Array HashTable |
| 036 |
Valid Sudoku |
Array HashSet |
| 048 |
Rotate Image |
Array |
| 053 |
Maximum Subarray |
Array |
| 065 |
Plus One |
Array |
| 069 |
Sqrt(x) |
Binary Search |
| 070 |
Climbing Stairs |
Dynamic Programming |
| 088 |
Merge Sorted Array |
Array Sorted |
| 083 |
Remove Duplicates from Sorted List |
Linked List |
| 098 |
Validate Binary Search Tree |
Tree |
| 100 |
Same Tree |
Tree |
| 101 |
Symmetric Tree |
Tree |
| 102 |
Binary Tree Level Order Traversal |
Tree |
| 104 |
Maximum Depth of Binary Tree |
Tree |
| 107 |
Binary Tree Level Order Traversal II |
Tree |
| 108 |
Convert Sorted Array to Binary Search Tree |
Tree |
| 110 |
Balanced Binary Tree |
Tree |
| 111 |
Minimum Depth of Binary Tree |
Tree |
| 112 |
Path Sum |
Tree |
| 122 |
Best Time to Buy and Sell Stock II |
Array |
| 125 |
Valid Palindrome |
String Array |
| 136 |
Single Number |
Array |
| 141 |
Linked List Cycle |
LinkedList |
| 160 |
Intersection of Two Linked Lists |
Linked List |
| 167 |
Two Sum II - Input array is sorted |
Array HashTable |
| 169 |
Majority Element |
Array |
| 171 |
Excel Sheet Column Number |
Math |
| 189 |
Rotate Array |
Array |
| 202 |
Happy Number |
Math |
| 203 |
Remove Linked List Elements |
Linked List |
| 206 |
Reverse a singly linked list |
LinkedList |
| 217 |
Contains Duplicate |
Array |
| 226 |
Invert Binary Tree |
Binary Tree |
| 234 |
Palindrome Linked List |
LinkedList |
| 235 |
Lowest Common Ancestor of a Binary Search Tree |
Tree |
| 237 |
Delete Node in a Linked List |
LinkedList |
| 242 |
Valid Anagram |
String Array |
| 257 |
Binary Tree Paths |
Tree |
| 268 |
Missing Number |
Math |
| 278 |
First Bad Version |
Array |
| 283 |
Move Zeroes |
Array |
| 290 |
Word Pattern |
Hash Table |
| 344 |
Reverse String |
String |
| 349 |
Intersection of Two Arrays |
HashTable BinarySearch |
| 350 |
Intersection of Two Arrays II |
Array Sort |
| 367 |
Valid Perfect Square |
Binary Search |
| 371 |
Sum of Two Integers |
Bit Manipulation |
| 374 |
Guess Number Higher or Lower |
Binary Search |
| 387 |
First Unique Character in a String |
String HashTable |
| 404 |
Sum of Left Leaves |
Tree |
| 412 |
Fizz Buzz |
Array |
| 429 |
N-ary Tree Level Order Traversal |
Tree |
| 437 |
Path Sum III |
Tree |
| 441 |
Arranging Coins |
Math |
| 501 |
Find Mode in Binary Search Tree |
Tree |
| 530 |
Minimum Absolute Difference in BST |
Tree |
| 538 |
Convert BST to Greater Tree |
Tree |
| 543 |
Diameter of Binary Tree |
Tree |
| 559 |
Maximum Depth of N-ary Tree |
Tree |
| 563 |
Binary Tree Tilt |
Tree |
| 572 |
Subtree of Another Tree |
Tree |
| 589 |
N-ary Tree Preorder Traversal |
Tree |
| 590 |
N-ary Tree Postorder Traversal |
Tree |
| 606 |
Construct String from Binary Tree |
Tree |
| 617 |
Merge Two Binary Trees |
Binary Tree |
| 637 |
Average of Levels in Binary Tree |
Tree |
| 653 |
Two Sum IV - Input is a BST |
Tree |
| 669 |
Trim a Binary Search Tree |
Tree |
| 671 |
Second Minimum Node In a Binary Tree |
Tree |
| 682 |
Baseball Game |
Stack |
| 687 |
Longest Univalue Path |
Tree |
| 700 |
Search in a Binary Search Tree |
Binary Tree |
| 707 |
Design Linked List |
Linked List |
| 709 |
To Lower Case |
String |
| 744 |
Find Smallest Letter Greater Than Target |
Array HashTable |
| 783 |
Minimum Distance Between BST Nodes |
Tree |
| 844 |
Backspace String Compare |
Stack Two Pointer |
| 852 |
Peak Index in a Mountain Array |
Binary Search |
| 876 |
Middle of the Linked List |
Linked List |
| 872 |
Leaf-Similar Trees |
Tree |
| 897 |
Increasing Order Search Tree |
Tree |
| 905 |
Sort-array-by-parity |
Array |
