DSA Solutions

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• Contains Duplicate
• Best Time to Buy and Sell Stock
• Valid Anagram
• Valid Parentheses
• Two Sum II
• Group Anagrams
• Product of Array Except Self
• Longest Substring Without Repeating Characters
• 3Sum

Problem List

Array

1. Two Sum Easy ⧖ Solution [x]
2. Best Time to Buy and Sell Stock Easy [ ]
3. Contains Duplicate Easy [ ]
4. Contains Duplicate II Easy
5. Product of Array Except Self Medium
6. Maximum Subarray Medium
7. Maximum Product Subarray Medium
8. Find Minimum in Rotated Sorted Array Medium
9. Search in Rotated Sorted Array Medium
10. Two Sum II Medium [ ]
11. 3Sum Medium [ ]
12. Container With Most Water Medium
13. Verifying an Alien Dictionary Easy
14. Next Permutation Medium
15. Remove Duplicates from Sorted Array Medium
16. Find First and Last Position of Element in Sorted Array Medium
17. Trapping Rain Water Hard
18. Median of Two Sorted Arrays Hard

Dynamic Programming

19. Climbing Stairs Easy
20. Coin Change Medium
21. Longest Increasing Subsequence Medium
22. Longest Common Subsequence Medium
23. Word Break Medium
24. Combination Sum Medium
25. House Robber Medium
26. House Robber II Medium
27. Decode Ways Medium
28. Unique Paths Medium
29. Pascal's Triangle Easy
30. Generate Parentheses Medium
31. Jump Game Medium
32. Jump Game II Medium
33. Regular Expression Matching Hard
34. Race Car Hard

Graph

35. Clone Graph Medium
36. Course Schedule Medium
37. Course Schedule II Medium
38. Pacific Atlantic Water Flow Medium
39. Number of Islands Medium
40. Longest Consecutive Sequence Medium
41. Alien Dictionary Hard (Premium)
42. Graph Valid Tree Medium (Premium)
43. Number of Provinces Medium
44. Find the Celebrity Medium
45. Number of Connected Components in an Undirected Graph Medium (Premium)

Hashing

46. Roman to Integer Easy
47. Copy List with Random Pointer Medium
48. Word Ladder Hard
49. First Missing Positive Hard

Interval

50. Insert Interval Medium
51. Merge Intervals Medium
52. Non-overlapping Intervals Medium
53. Remove Interval Medium
54. Meeting Rooms Easy (Premium)
55. Meeting Rooms II Medium (Premium)

Linked List

56. Add Two Numbers Medium
57. Reverse Linked List Easy
58. Linked List Cycle Easy
59. Merge Two Sorted Lists Easy
60. Merge K Sorted Lists Hard
61. Remove Nth Node From End of List Medium
62. Reorder List Medium
63. Middle of the Linked List Easy
64. Flatten Binary Tree to Linked List Medium
65. Reverse Nodes in k-Group Hard

Matrix

66. Set Matrix Zeroes Medium
67. Spiral Matrix Medium
68. Rotate Image Medium
69. Longest Increasing Path in a Matrix Hard
70. Word Search Medium
71. Valid Sudoku Medium
72. Game of Life Medium

Design

73. LRU Cache Medium
74. Insert Delete GetRandom O(1) Medium
75. Logger Rate Limiter Easy
76. Design Tic-Tac-Toe Medium
77. Moving Average from Data Stream Easy

Sorting

78. Merge Sorted Array Easy
79. Largest Number Medium
80. Sort List Medium
81. Sort Colors Medium
82. Majority Element Easy

String

83. Longest Substring Without Repeating Characters Medium
84. Longest Repeating Character Replacement Medium
85. Fizz Buzz Easy
86. Longest Common Prefix Easy
87. Minimum Window Substring Hard
88. Valid Anagram Easy [ ]
89. Group Anagrams Medium
90. Valid Parentheses Easy
91. Valid Palindrome Easy
92. Longest Palindromic Substring Medium
93. Letter Combinations of a Phone Number Medium
94. Palindromic Substrings Medium
95. Encode and Decode Strings Medium (Premium)
96. Palindrome Linked List Easy
97. Text Justification Hard

Stack

98. Min Stack Medium
99. Largest Rectangle in Histogram Hard
100. Minimum Remove to Make Valid Parentheses Medium
101. Longest Valid Parentheses Hard
102. Max Stack Hard

Tree

103. Maximum Depth of Binary Tree Easy
104. Same Tree Easy
105. Symmetric Tree Easy
106. Invert Binary Tree Easy
107. Binary Tree Maximum Path Sum Hard
108. Binary Tree Level Order Traversal Medium
109. Serialize and Deserialize Binary Tree Hard
110. Subtree of Another Tree Easy
111. Find Leaves of Binary Tree Medium
112. Construct Binary Tree from Preorder and Inorder Traversal Medium
113. Validate Binary Search Tree Medium
114. Kth Smallest Element in a BST Medium
115. Lowest Common Ancestor of a Binary Search Tree Medium
116. Binary Tree Zigzag Level Order Traversal Medium
117. Implement Trie (Prefix Tree) Medium
118. Add and Search Word Medium
119. Word Search II Hard

Heap

120. High Five Easy
121. Top K Frequent Elements Medium
122. Kth Largest Element in an Array Medium
123. Sliding Window Maximum Hard
124. Find Median from Data Stream Hard
125. Employee Free Time Hard

Bit Manipulation

126. Sum of Two Integers Medium
127. Number of 1 Bits Easy
128. Counting Bits Easy
129. Missing Number Easy
130. Reverse Bits Easy