Leetcode Solutions

Best Time to Buy and Sell Stock

#	Title	Difficulty	Blog	Others
121	Best Time to Buy and Sell Stock	Easy	Best Time to Buy and Sell Stock
122	Best Time to Buy and Sell Stock	Easy	Best Time to Buy and Sell Stock
123	Best Time to Buy and Sell Stock III	Hard	Best Time to Buy and Sell Stock III	dp
188	Best Time to Buy and Sell Stock IV	Hard	Best Time to Buy and Sell Stock IV	dp
309	Best Time to Buy and Sell Stock with Cooldown	Medium	Best Time to Buy and Sell Stock with Cooldown	dp
714	Best Time to Buy and Sell Stock with Transaction Fee	Medium	Best Time to Buy and Sell Stock with Transaction Fee	dp

Path Sum

#	Title	Difficulty	Blog	Others
112	Path Sum	Easy	Path Sum
113	Path Sum II	Medium	Path Sum II
437	Path Sum III	Easy	Path Sum III

House Robber

#	Title	Difficulty	Blog	Others
198	House Robber	Easy	House Robber	dp
213	House Robber II	Easy	House Robber II	dp
337	House Robber III	Medium	House Robber III	dp

Binary Tree Traversal

#	Title	Difficulty	Blog	Others
144	Binary Tree Preorder Traversal	Medium	Binary Tree Preorder Traversal
94	Binary Tree Inorder Traversal	Medium	Binary Tree Inorder Traversal
145	Binary Tree Postorder Traversal	Hard	Binary Tree Postorder Traversal
102	Binary Tree Level Order Traversal	Medium	Binary Tree Level Order Traversal	* Binary-Tree Traverse
107	Binary Tree Level Order Traversal II	Easy	Binary Tree Level Order Traversal II	* Binary-Tree Traverse

Find Number Disappear or Duplicate in Array

#	Title	Difficulty	Blog	Others
41	First Missing Positive	Hard	First Missing Positive
287	Find the Duplicate Number	Medium	Find the Duplicate Number	fast-slow-pointer
442	Find All Duplicates in an Array	Medium	Find All Duplicates in an Array
448	Find All Numbers Disappeared in an Array	Easy	Find All Numbers Disappeared in an Array
645	Set Mismatch	Easy	Set Mismatch

Water Container

#	Title	Difficulty	Blog	Others
11	Container With Most Water	Medium	Container With Most Water
42	Trapping Rain Water	Hard	Trapping Rain Water	Dp/Stack/Two Pointer
407	Trapping Rain Water II	Hard	Trapping Rain Water II

Numbers represented by String

#	Title	Difficulty	Blog	Others
2	Add Two Numbers	Medium	Add Two Numbers
66	Plus One	Easy	Plus One
67	Add Binary	Easy	Add Binary

Palindrome

#	Title	Difficulty	Blog	Others
5	Longest Palindromic Substring	Medium	Longest Palindromic Substring	dp & Manacher’s Algorithm *
9	Palindrome Number	Easy	Palindrome Number

Integer and Roman

#	Title	Difficulty	Blog	Others
12	Integer to Roman	Medium	Integer to Roman
13	Roman to Integer	Easy	Roman to Integer

N Sum

#	Title	Difficulty	Blog	Others
1	Two Sum	Easy	Two Sum
15	3Sum	Medium	3Sum
16	3Sum Closest	Medium	3Sum Closest
18	4Sum	Medium	4Sum

Merge Sorted List

#	Title	Difficulty	Blog	Others
21	Merge Two Sorted Lists	Easy	Merge Two Sorted Lists
23	Merge k Sorted Lists	Hard	Merge k Sorted Lists	Divide Conquer & Heap Sort

Search in Sorted Array

#	Title	Difficulty	Blog	Others
33	Search in Rotated Sorted Array	Medium	Search in Rotated Sorted Array
34	Find First and Last Position of Element in Sorted Array	Medium	Find First and Last Position of Element in Sorted Array
35	Search Insert Position	Easy	Search Insert Position

Sudoku

#	Title	Difficulty	Blog	Others
36	Valid Sudoku	Medium	Valid Sudoku
37	Sudoku Solver	Hard	Sudoku Solver	Backtracking *

Longest Subsequence

#	Title	Difficulty	Blog	Others
300	Longest Increasing Subsequence	Medium	Longest Increasing Subsequence	dp
873	Length of Longest Fibonacci Subsequence	Medium	Length of Longest Fibonacci Subsequence	dp

Combination Sum

#	Title	Difficulty	Blog	Others
39	Combination Sum	Medium	Combination Sum	backtracing
40	Combination Sum II	Medium	Combination Sum II	backtracing
216	Combination Sum III	Medium	Combination Sum III	backtracing
377	Combination Sum IV	Medium	Combination Sum IV	dp