Leetcode

This notebook records the Leetcode problems I have solved.

Solved Leetcode Problems

In chronological order:

Date	Problem	type
5/15/2022	3Sum, 3Sum Closest	array
5/16/2022	Longest Substring Without Repeating Characters, Longest Palindromic Substring	string
5/17/2022	Container With Most Water, Remove Nth Node From End of List	two pointers
5/18/2022	Add Two Numbers, Merge Two Sorted Lists	linked list
5/19/2022	Valid Parentheses	stack
5/20/2022	Simplify Path	stack
5/21/2022	Binary Tree Inorder Traversal, Unique Binary Search Trees	tree
5/27/2022	Generate Parentheses	dynamic programming
7/27/2022	Letter Combinations of a Phone Number	Backtracking
7/29/2022	Combination Sum	Backtracking
8/16/2022	Validate Binary Search Tree	DFS
8/17/2022	Recover Binary Search Tree	DFS
8/18/2022	Same Tree, Symmetric Tree	BFS
8/19/2022	Search in Rotated Sorted Array	Binary Search
8/20/2022	Linked List Cycle II	Linked List
8/22/2022	First Bad Version, Sqrt(x), Search Insert Position	Binary Search
8/25/2022	Capacity to Ship Packages Within D Days	Binary Search
8/27/2022	Reverse Integer, Palindrome Number, Two Sum	Math, Hash Table
9/8/2022	Group Anagrams, Merge Intervals	Sorting
9/10/2022	Add Binary	Bit Manipulation
9/17/2022	Longest Consecutive Sequence	Union Find
01/22/2024	Merge Strings Alternately, Reverse Words in a String	String
01/23/2024	Greatest Common Divisor of Strings, Product of Array Except Self	String, Array
01/24/2024	Kids With the Greatest Number of Candies, Increasing Triplet Subsequence	Array
08/03/2024	Reverse Vowels of a String	Two Pointers

In numerical order:

Number	Title	Difficulty
1	Two Sum	Easy
2	Add Two Numbers	Medium
3	Longest Substring Without Repeating Characters	Medium
5	Longest Palindromic Substring	Medium
7	Reverse Integer	Medium
9	Palindrome Number	Easy
11	Container With Most Water	Medium
15	3Sum	Medium
16	3Sum Closest	Medium
17	Letter Combinations of a Phone Number	Medium
19	Remove Nth Node From End of List	Medium
20	Valid Parentheses	Easy
21	Merge Two Sorted Lists	Easy
22	Generate Parentheses	Medium
33	Search in Rotated Sorted Array	Medium
35	Search Insert Position	Easy
39	Combination Sum	Medium
49	Group Anagrams	Medium
56	Merge Intervals	Medium
67	Add Binary	Easy
69	Sqrt(x)	Easy
71	Simplify Path	Medium
94	Binary Tree Inorder Traversal	Easy
96	Unique Binary Search Trees	Medium
98	Validate Binary Search Tree	Medium
99	Recover Binary Search Tree	Medium
100	Same Tree	Easy
101	Symmetric Tree	Easy
128	Longest Consecutive Sequence	Medium
142	Linked List Cycle II	Medium
151	Reverse Words in a String	Medium
238	Product of Array Except Self	Medium
278	First Bad Version	Easy
334	Increasing Triplet Subsequence	Medium
345	Reverse Vowels of a String	Easy
1011	Capacity to Ship Packages Within D Days	Medium
1071	Greatest Common Divisor of Strings	Easy
1431	Kids With the Greatest Number of Candies	Easy
1768	Merge Strings Alternately	Easy

Resources

• https://books.halfrost.com/leetcode/

• Coding Interview Preparation - Kaiyu Zheng