LeetCode

Easy Medium Hard
Leetcode List

Stack and Queue

Binary Tree
144. Binary Tree Preorder Traversal Easy
94. Binary Tree Inorder Traversal Easy
145. Binary Tree Postorder Traversal Easy
102. Binary Tree Level Order Traversal Medium
107. Binary Tree Level Order Traversal II Medium
199. Binary Tree Right Side View Easy
637. Average of Levels in Binary Tree Easy
429. N-ary Tree Level Order Traversal Easy
515. Find Largest Value in Each Tree Row Easy
116. Populating Next Right Pointers in Each Node Easy
117. Populating Next Right Pointers in Each Node II Easy
104. Maximum Depth of Binary Tree Easy
111. Minimum Depth of Binary Tree Easy
226. Invert Binary Tree Easy
101. Symmetric Tree Easy
559. Maximum Depth of N-ary Tree Easy
222. Count Complete Tree Nodes Easy
110. Balanced Binary Tree Easy
257. Binary Tree Paths Easy
404. Sum of Left Leaves Easy
513. Find Bottom Left Tree Value Easy
112. Path Sum Easy
113. Path Sum II Easy
106. Construct Binary Tree from Inorder and Postorder Traversal Easy
105. Construct Binary Tree from Preorder and Inorder Traversal Easy
654. Maximum Binary Tree Easy
617. Merge Two Binary Trees Easy
700. Search in a Binary Search Tree Easy
98. Validate Binary Search Tree Easy
530. Minimum Absolute Difference in BST Easy
501. Find Mode in Binary Search Tree Easy
236. Lowest Common Ancestor of a Binary Tree Easy
235. Lowest Common Ancestor of a Binary Search Tree Easy
701. Insert into a Binary Search Tree Easy
450. Delete Node in a BST Easy
669. Trim a Binary Search Tree Easy
108. Convert Sorted Array to Binary Search Tree Easy
538. Convert BST to Greater Tree Easy

Backtracking Algorithm
77. Combinations Medium
216. Combination Sum III Medium
17. Letter Combinations of a Phone Number Medium
39. Combination Sum Medium
40. Combination Sum II Medium
131. Palindrome Partitioning Medium
93. Restore IP Addresses Medium
78. Subsets Medium
90. Subsets II Medium
491. Non-decreasing Subsequences Medium
46. Permutations Medium
47. Permutations II Medium
332. Reconstruct Itinerary Hard
51. N-Queens Hard
37. Sudoku Solver Hard

**************************** Greedy Algorithm ***************************

************************* Dynamic Programming *************************

509. Fibonacci Number Easy
70. Climbing Stairs Easy
746. Min Cost Climbing Stairs Easy
62. Unique Paths Medium
63. Unique Paths II Medium
343. Integer Break Medium
96. Unique Binary Search Trees Medium
416. Partition Equal Subset Sum Medium
1049. Last Stone Weight II Medium
494. Target Sum Medium
474. Ones and Zeroes Medium
518. Coin Change II Medium
377. Combination Sum IV Medium
70. Climbing Stairs Easy
322. Coin Change Medium
279. Perfect Squares Medium
139. Word Break Medium

Robber and Stock Problem
198. House Robber Medium
213. House Robber II Medium
337. House Robber III Medium
121. Best Time to Buy and Sell Stock Easy
122. Best Time to Buy and Sell Stock II Medium
123. Best Time to Buy and Sell Stock III Hard
188. Best Time to Buy and Sell Stock IV Hard
309. Best Time to Buy and Sell Stock with Cooldown Medium
714. Best Time to Buy and Sell Stock with Transaction Fee Medium

Subsequence Problem
300. Longest Increasing Subsequence Medium
674. Longest Continuous Increasing Subsequence Easy
718. Maximum Length of Repeated Subarray Medium
1143. Longest Common Subsequence Medium
1035. Uncrossed Lines Medium
53. Maximum Subarray Medium
392. Is Subsequence Easy
115. Distinct Subsequences Hard
583. Delete Operation for Two Strings Medium
72. Edit Distance Medium
647. Palindromic Substrings Medium
516. Longest Palindromic Subsequence Medium

Array
Linked List
Hash Table
String


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