TristanWYL / leetcode.py

Leetcode solution in python with clear explanation

Leetcode solutions in Python

Features:

✅ Clear explanation
✅ Time complexity and space complexity
✅ Some problems may include more than one solution

Actively being updated. STAY TUNED!

List

#	Title	Categories	Difficulty
1	Two Sum	iteration and dict	Easy
3	Longest Substring Without Repeating Characters	dp	Medium
5	Longest Palindromic Substring	dp	Medium
7	Reverse Integer	n/a	Medium
9	Palindrome Number	n/a	Easy
10	Regular Expression Matching	dp	Hard
12	Integer to Roman	n/a	Medium
13	Roman to Integer	n/a	Easy
14	Longest Common Prefix	n/a	Easy
15	3Sum	n/a	Medium
16	3Sum Closest	n/a	Medium
17	Letter Combinations of a Phone Number	n/a	Medium
18	4Sum	n/a	Medium
19	Remove Nth Node From End of List	linked list	Medium
20	Valid Parentheses	n/a	Easy
22	Generate Parentheses	n/a	Medium
24	Swap Nodes in Pairs	linked list	Medium
26	Remove Duplicates from Sorted Array	n/a	Easy
27	Remove Element	n/a	Easy
31	Next Permutation	n/a	Medium
35	Search Insert Position	bisection	Easy
38	Count and Say	n/a	Medium
39	Combination Sum	backtrack dp	Medium
43	Multiply Strings	n/a	Medium
46	Permutations	backtrack DFS BFS	Medium
47	Permutations II	backtrack DFS BFS	Medium
77	Combinations	backtrack DFS BFS	Medium
92	Reverse Linked List II	n/a	Medium
100	Same Tree	binary tree	Easy
101	Symmetric Tree	binary tree	Easy
104	Maximum Depth of Binary Tree	binary tree	Easy
110	Balanced Binary Tree	binary tree	Easy
111	Minimum Depth of Binary Tree	binary tree	Easy
114	Flatten Binary Tree to Linked List	binary tree	Medium
121	Best Time to Buy and Sell Stock	dp	Easy
122	Best Time to Buy and Sell Stock II	dp	Medium
141	Linked List Cycle	linked list	Easy
142	Linked List Cycle II	linked list	Medium
206	Reverse Linked List	linked list	Easy
207	Course Schedule	graph	Medium
210	Course Schedule II	graph	Medium
226	Invert Binary Tree	binary tree	Easy
234	Palindrome Linked List	linked list	Easy
257	Binary Tree Paths	binary tree	Easy
295	Find Median from Data Stream	heap	Hard
300	Longest Increasing Subsequence	dp	Medium
322	Coin Change	dp	Medium
354	Russian Doll Envelopes	dp	Hard
382	Linked List Random Node	linked list	Medium
430	Flatten a Multilevel Doubly Linked List	linked list	Medium
475	Heaters	bisection	Medium
494	Target Sum	backtrack dp	Medium
509	Fibonacci Number	n/a	Easy
563	Binary Tree Tilt	binary tree	Easy
654	Maximum Binary Tree	binary tree	Medium
655	Print Binary Tree	binary tree	Medium
707	Design Linked List	linked list	Medium
719	Find K-th Smallest Pair Distance	bisection	Hard
725	Split Linked List in Parts	linked list	Medium
752	Open the Lock	n/a	Medium
797	All Paths From Source to Target	graph	Medium
817	Linked List Components	linked list	Medium
857	Minimum Cost to Hire K Workers	heap	Hard
875	Koko Eating Bananas	bisection	Medium
931	Minimum Falling Path Sum	dp	Medium
965	Univalued Binary Tree	binary tree	Easy
968	Binary Tree Cameras	binary tree	Hard
1439	Find the Kth Smallest Sum of a Matrix With Sorted Rows	heap	Hard
1449	Form Largest Integer With Digits That Add up to Target	dp	Hard
1609	Even Odd Tree	binary tree	Medium