Leetcode Top Interview 150

This repository contains my solutions to the Leetcode Top Interview 150 problems.

Id	Problem	Difficulty	Signal	Status
Array / String
1	Merge Sorted Array	Easy	🟢	✅
2	Remove Element	Easy	🟢	✅
3	Remove Duplicates from Sorted Array	Easy	🟢	✅
4	Remove Duplicates from Sorted Array II	Medium	🟡
5	Majority Element	Easy	🟢	✅
6	Rotate Array	Medium	🟡
7	Best Time to Buy and Sell Stock	Easy	🟢	✅
8	Best Time to Buy and Sell Stock II	Medium	🟡
9	Jump Game	Medium	🟡
10	Jump Game II	Medium	🟡
11	H-Index	Medium	🟡
12	Insert Delete GetRandom O(1)	Medium	🟡
13	Product of Array Except Self	Medium	🟡
14	Gas Station	Medium	🟡
15	Candy	Hard	🔴
16	Trapping Rain Water	Hard	🔴
17	Roman to Integer	Easy	🟢	✅
18	Integer to Roman	Medium	🟡
19	Length of Last Word	Easy	🟢	✅
20	Longest Common Prefix	Easy	🟢	✅
21	Reverse Words in a String	Medium	🟡
22	Zigzag Conversion	Medium	🟡
23	Find the Index of the First Occurrence in a String	Easy	🟢	✅
24	Text Justification	Hard	🔴
Two Pointers
25	Valid Palindrome	Easy	🟢	✅
26	Is Subsequence	Easy	🟢	✅
27	Two Sum II - Input Array Is Sorted	Medium	🟡
28	Container With Most Water	Medium	🟡
29	3Sum	Medium	🟡
Sliding Window
30	Minimum Size Subarray Sum	Medium	🟡
31	Longest Substring Without Repeating Characters	Medium	🟡
32	Substring with Concatenation of All Words	Hard	🔴
33	Minimum Window Substring	Hard	🔴
Matrix
34	Valid Sudoku	Medium	🟡	✅
35	Spiral Matrix	Medium	🟡
36	Rotate Image	Medium	🟡
37	Set Matrix Zeroes	Medium	🟡
38	Game of Life	Medium	🟡
Hashmap
39	Ransom Note	Easy	🟢	✅
40	Isomorphic Strings	Easy	🟢	✅
41	Word Pattern	Easy	🟢	✅
42	Valid Anagram	Easy	🟢	✅
43	Group Anagrams	Medium	🟡
44	Two Sum	Easy	🟢	✅
45	Happy Number	Easy	🟢	✅
46	Contains Duplicate II	Easy	🟢	✅
47	Longest Consecutive Sequence	Medium	🟡
Intervals
48	Summary Ranges	Easy	🟢	✅
49	Merge Intervals	Medium	🟡
50	Insert Interval	Medium	🟡
51	Minimum Number of Arrows to Burst Balloons	Medium	🟡
Stack
52	Valid Parentheses	Easy	🟢	✅
53	Simplify Path	Medium	🟡
54	Min Stack	Medium	🟡
55	Evaluate Reverse Polish Notation	Medium	🟡
56	Basic Calculator	Hard	🔴
Linked List
57	Linked List Cycle	Easy	🟢	✅
58	Add Two Numbers	Medium	🟡
59	Merge Two Sorted Lists	Easy	🟢	✅
60	Copy List with Random Pointer	Medium	🟡
61	Reverse Linked List II	Medium	🟡
62	Reverse Nodes in k-Group	Hard	🔴
63	Remove Nth Node From End of List	Medium	🟡
64	Remove Duplicates from Sorted List II	Medium	🟡
65	Rotate List	Medium	🟡
66	Partition List	Medium	🟡
67	LRU Cache	Medium	🟡	✅
Binary Tree General
68	Maximum Depth of Binary Tree	Easy	🟢	✅
69	Same Tree	Easy	🟢	✅
70	Invert Binary Tree	Easy	🟢	✅
71	Symmetric Tree	Easy	🟢	✅
72	Construct Binary Tree from Preorder and Inorder Traversal	Medium	🟡
73	Construct Binary Tree from Inorder and Postorder Traversal	Medium	🟡
74	Populating Next Right Pointers in Each Node II	Medium	🟡
75	Flatten Binary Tree to Linked List	Medium	🟡
76	Path Sum	Easy	🟢	✅
77	Sum Root to Leaf Numbers	Medium	🟡
78	Binary Tree Maximum Path Sum	Hard	🔴
79	Binary Search Tree Iterator	Medium	🟡
80	Count Complete Tree Nodes	Easy	🟢	✅
81	Lowest Common Ancestor of a Binary Tree	Medium	🟡
Binary Tree BFS
8282	Binary Tree Right Side View	Medium	🟡
83	Average of Levels in Binary Tree	Easy	🟢	✅
84	Binary Tree Level Order Traversal	Medium	🟡	✅
85	Binary Tree Zigzag Level Order Traversal	Medium	🟡
Binary Search Tree
86	Minimum Absolute Difference in BST	Easy	🟢	✅
87	Kth Smallest Element in a BST	Medium	🟡
88	Validate Binary Search Tree	Medium	🟡
Graph General
89	Number of Islands	Medium	🟡
90	Surrounded Regions	Medium	🟡
91	Clone Graph	Medium	🟡
92	Evaluate Division	Medium	🟡
93	Course Schedule	Medium	🟡
94	Course Schedule II	Medium	🟡
Graph BFS
95	Snakes and Ladders	Medium	🟡
96	Minimum Genetic Mutation	Medium	🟡
97	Word Ladder	Hard	🔴
Trie
98	Implement Trie (Prefix Tree)	Medium	🟡
99	Design Add and Search Words Data Structure	Medium	🟡
100	Word Search II	Hard	🔴
Backtracking
101	Letter Combinations of a Phone Number	Medium	🟡
102	Combinations	Medium	🟡
103	Permutations	Medium	🟡
104	Combination Sum	Medium	🟡
105	N-Queens II	Hard	🔴
106	Generate Parentheses	Medium	🟡
107	Word Search	Medium	🟡
Divide & Conquer
108	Convert Sorted Array to Binary Search Tree	Easy	🟢	✅
109	Sort List	Medium	🟡
110	Construct Quad Tree	Medium	🟡
111	Merge k Sorted Lists	Hard	🔴
Kadane's Algorithm
112	Maximum Subarray	Medium	🟡
113	Maximum Sum Circular Subarray	Medium	🟡
Binary Search
114	Search Insert Position	Easy	🟢	✅
115	Search a 2D Matrix	Medium	🟡
116	Find Peak Element	Medium	🟡
117	Search in Rotated Sorted Array	Medium	🟡
118	Find First and Last Position of Element in Sorted Array	Medium	🟡
119	Find Minimum in Rotated Sorted Array	Medium	🟡
120	Median of Two Sorted Arrays	Hard	🔴
Heap
121	Kth Largest Element in an Array	Medium	🟡
122	IPO	Hard	🔴
123	Find K Pairs with Smallest Sums	Medium	🟡
124	Find Median from Data Stream	Hard	🔴
Bit Manipulation
125	Add Binary	Easy	🟢	✅
126	Reverse Bits	Easy	🟢	✅
127	Number of 1 Bits	Easy	🟢	✅
128	Single Number	Easy	🟢	✅
129	Single Number II	Medium	🟡
130	Bitwise AND of Numbers Range	Medium	🟡
Math
131	Palindrome Number	Easy	🟢	✅
132	Plus One	Easy	🟢	✅
133	Factorial Trailing Zeroes	Medium	🟡
134	Sqrt(x)	Easy	🟢	✅
135	Pow(x, n)	Medium	🟡
136	Max Points on a Line	Hard	🔴
1D DP
137	Climbing Stairs	Easy	🟢
138	House Robber	Medium	🟡
139	Word Break	Medium	🟡
140	Coin Change	Medium	🟡
141	Longest Increasing Subsequence	Medium	🟡
Multidimensional DP
142	Triangle	Medium	🟡
143	Minimum Path Sum	Medium	🟡
144	Unique Paths II	Medium	🟡
145	Longest Palindromic Substring	Medium	🟡
146	Interleaving String	Medium	🟡
147	Edit Distance	Medium	🟡
148	Best Time to Buy and Sell Stock III	Hard	🔴
149	Best Time to Buy and Sell Stock IV	Hard	🔴
150	Maximal Square	Medium	🟡