Use Python/Java to Solve Problems in LeetCode Progress Tracker Idx Date Question Python Java Domain Tag Difficulty Remark 001 20190626 54. Spiral Matrix 054p 054j Matrix Medium 002 20190626 59. Spiral Matrix II 059p 059j Matrix Medium 003 20190627 53. Maximum Subarray 053p 053j Array DP Easy 004 20190627 220. Contains Duplicate III 220p 220j Array Medium 005 20191013 101. Symmetric Tree 101p 101j Tree Recursive Easy 006 20191013 102. Binary Tree Level Order Traversal 102p 102j Tree Iterative Medium 007 20191020 104. Maximum Depth of Binary Tree 104p 104j Tree BFS/DFS Easy 008 20191027 509. Fibonacci Number 509p 509j Array DP Easy 009 20191110 3. Longest Substring Without Repeating Characters 003p 003j String Medium 010 20191117 206. Reverse Linked List 206p 206j List Easy 011 20191117 147. Insertion Sort List 147p 147j List Sort Medium 012 20191124 155. Min Stack 155p 155j Stack Easy 013 20191124 946. Validate Stack Sequences 946p 946j Stack Medium 014 20191215 225. Implement Stack using Queues 225p 225j Stack Easy 015 20191215 148. Sort List 148p 148j List Sort Medium 016 20191215 876. Middle of the Linked List 876p 876j List Easy 017 20191215 152. Maximum Product Subarray 152p 152j Array DP Medium 018 20191228 144. Binary Tree Preorder Traversal 144p 144j Tree Iterative Medium 019 20191228 94. Binary Tree Inorder Traversal 094p 094j Tree Iterative Medium 020 20191228 704. Binary Search 704p 704j Array Search Easy 021 20191229 145. Binary Tree Postorder Traversal 145p 145j Tree Iterative Hard 022 20191229 563. Binary Tree Tilt 563p 563j Tree Recursive Easy 023 20200216 35. Search Insert Position 035p 035j List Search Easy 024 20200216 27. Remove Element 027p 027j Easy 025 20200216 2. Add Two Numbers 002p 002j List Medium 026 20200223 530. Minimum Absolute Difference in BST 530p 530j BST Recursive Easy 027 20200301 938. Range Sum of BST 938p 938j BST Recursive/Iterative Easy 028 20200301 450. Delete Node in a BST 450p 450j BST Recursive Medium 029 20200329 538. Convert BST to Greater Tree 538p 538j BST Recursive/Iterative Easy 030 20200329 1. Two Sum 001p 001j Array HashTable Easy 031 20200329 653. Two Sum IV - Input is a BST 653p 653j BST Easy 032 20200406 226. Invert Binary Tree 226p 226j Tree Recursive/Iterative Easy 033 20200406 110. Balanced Binary Tree 110p 110j Tree Recursive Easy 034 20200406 96. Unique Binary Search Trees 096p 096j BST DP Medium 035 20200406 95. Unique Binary Search Trees II 095p 095j BST DP Medium 036 20200419 912. Sort an Array 912p 912j List Sort Medium 037 20200419 540. Single Element in a Sorted Array 540p 540j List Search Medium 038 20200419 88. Merge Sorted Array 088p 088j List Easy 039 20200425 705. Design HashSet 705p 705j Hash Easy 040 20200425 13. Roman to Integer 013p 013j Math Easy 041 20200425 12. Integer to Roman 012p 012j Math Medium 042 20200627 108. Convert Sorted Array to Binary Search Tree 108p 108j BST Recursive Easy 043 20200627 109. Convert Sorted List to Binary Search Tree 109p 109j BST Recursive Medium 044 20200705 28. Implement strStr() 028p 028j String KMP Easy 045 20200816 56. Merge Intervals 056p 056j Sort Medium 046 20200816 57. Insert Interval 057p 057j Sort Hard 047 20210822 300. Longest Increasing Subsequence 300p 300j List DP Medium 048 20210822 78. Subsets 078p 078j List Medium