leetcode-python-java

Not only Python & Java solutions for LeetCode problems, but also =>

LeetCode Python/Java/JavaScript/C#/Go/Ruby Solutions

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Hi there! I'm Lane. Do you feel that there are too many problems (over 3,450) on the LeetCode and you can't finish them all? Or do you forget how to solve the problems you did last time?

If you can master some solution patterns, this will happen less often.

Here, I will provide you with common problem-solving patterns so that you don't waste time on problems that are not often tested in interviews.

Python, C++, Java, JavaScript, C#, Go, Ruby languages' solutions are provided for every selected LeetCode problem. Other languages' solutions will be provided in the future. If you have better solutions, welcome to create an issue or PR!

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How to Use this "leetcode-python-java" Repository?

I have planned a learning route for you. You just need to do the problems in the order they are listed. You can skip the more difficult problems and do them later.

Array

344. Reverse String Python, Java, C++, JavaScript, C#, Go, Ruby.
27. Remove Element Python, Java, C++, JavaScript, C#, Go, Ruby, 2 approaches.
605. Can Place Flowers Python, Java, C++, JavaScript, C#, Go, Ruby.
238. Product of Array Except Self Python, Java, C++, JavaScript, C#, Go, Ruby.
704. Binary Search Python, Java, C++, JavaScript, C#, Go, Ruby.
977. Squares of a Sorted Array Python, Java, C++, JavaScript, C#, Go, Ruby.
209. Minimum Size Subarray Sum Python, Java, C++, JavaScript, C#, Go, Ruby.
303. Range Sum Query - Immutable Python, Java, C++, JavaScript, C#, Go, Ruby.
59. Spiral Matrix II Python, Java, C++, JavaScript, C#, Go, Ruby.
503. Next Greater Element II Python, Java, C++, JavaScript, C#, Go, Ruby.
3478. Choose K Elements With Maximum Sum Python.

Linked List

203. Remove Linked List Elements Python, Java, C++, JavaScript, C#, Go, Ruby.
206. Reverse Linked List Python, Java, C++, JavaScript, C#, Go, Ruby.
160. Intersection of Two Linked Lists Python, Java, C++, JavaScript, C#, Go, Ruby.
19. Remove Nth Node From End of List Python, Java, C++, JavaScript, C#, Go, Ruby.
707. Design Linked List Python, Java, C++, JavaScript, C#, Go, Ruby.
24. Swap Nodes in Pairs Python, Java, C++, JavaScript, C#, Go, Ruby.

Hash Table

349. Intersection of Two Arrays Python, Java, C++, JavaScript, C#, Go, Ruby.
242. Valid Anagram Python, Java, C++, JavaScript, C#, Go, Ruby.
1. Two Sum Python, Java, C++, JavaScript, C#, Go, Ruby.
383. Ransom Note Python, Java, C++, JavaScript, C#, Go, Ruby.
202. Happy Number Python, Java, C++, JavaScript, C#, Go, Ruby.
454. 4Sum II Python, Java, C++, JavaScript, C#, Go, Ruby.
49. Group Anagrams Python, Ruby.

String

28. Find the Index of the First Occurrence in a String Python, Java, C++, JavaScript, C#, Go, Ruby.
541. Reverse String II Python, Java, C++, JavaScript, C#, Go, Ruby.
1768. Merge Strings Alternately Python, Java, C++, JavaScript, C#, Go, Ruby.
1431. Kids With the Greatest Number of Candies Python, Java, C++, JavaScript, C#, Go, Ruby.
151. Reverse Words in a String Python, Java, C++, JavaScript, C#, Go, Ruby.
459. Repeated Substring Pattern Python, Java, C++, JavaScript, C#, Go, Ruby.
833. Find, Replace in String Python.
1071. Greatest Common Divisor of Strings Python, Java, C++, JavaScript, C#, Go, Ruby.

Two Pointers

345. Reverse Vowels of a String Python, Java, C++, JavaScript, C#, Go, Ruby.
15. 3Sum Python, Java, C++, JavaScript, C#, Go, Ruby, 2 approaches.
18. 4Sum Python, Java, C++, JavaScript, C#, Go, Ruby.

Stack & Queue

20. Valid Parentheses Python, Java, C++, JavaScript, C#, Go, Ruby.
232. Implement Queue using Stacks Python, Java, C++, JavaScript, C#, Go, Ruby.
225. Implement Stack using Queues Python, Java, C++, JavaScript, C#, Go, Ruby, 3 approaches.

Binary Tree

144. Binary Tree Preorder Traversal Python, 2 approaches.

Dynamic Programming

Easy Problems

509. Fibonacci Number Python, Java, C++, JavaScript, C#, Go, Ruby.

House Robber

198. House Robber Python, Java, C++, JavaScript, C#, Go, Ruby.
213. House Robber II Python, Java, C++, JavaScript, C#, Go, Ruby.
337. House Robber III Python, Java, C++, JavaScript, C#, Go, Ruby, 2 approaches.

Knapsack Problems

0/1 Knapsack

416. Partition Equal Subset Sum Python, Java, C++, JavaScript, C#, Go, Ruby, 2 approaches.
1049. Last Stone Weight II Python, Java, C++, JavaScript, C#, Go, Ruby, 2 approaches.
494. Target Sum Python, Java, C++, JavaScript, C#, Go, Ruby.
474. Ones and Zeroes Python, Java, C++, JavaScript, C#, Go, Ruby.

Unbounded Knapsack

518. Coin Change II Python, Java, C++, JavaScript, C#, Go, Ruby.
377. Combination Sum IV Python, Java, C++, JavaScript, C#, Go, Ruby.
322. Coin Change Python, Java, C++, JavaScript, C#, Go, Ruby.
279. Perfect Squares Python, Java, C++, JavaScript, C#, Go, Ruby.
139. Word Break Python, Java, C++, JavaScript, C#, Go, Ruby.

Stock Maximum Profit Problems

121. Best Time to Buy and Sell Stock Python, JavaScript, Go.
122. Best Time to Buy and Sell Stock II Python, JavaScript, Go.
714. Best Time to Buy and Sell Stock with Transaction Fee Python, JavaScript, Go.
123. Best Time to Buy and Sell Stock III Python, JavaScript, Go.
188. Best Time to Buy and Sell Stock IV Python, JavaScript, Go.
309. Best Time to Buy and Sell Stock with Cooldown Python, JavaScript, Go.

Subsequence Problems

674. Longest Continuous Increasing Subsequence Python, Java, JavaScript, C#.
300. Longest Increasing Subsequence Python, Java, JavaScript, C#.
718. Maximum Length of Repeated Subarray Python, Java, JavaScript, C#.
1143. Longest Common Subsequence Python, Java, C++, JavaScript, C#, Go, Ruby.
1035. Uncrossed Lines Python, Java, C++, JavaScript, C#, Go, Ruby.
53. Maximum Subarray Python, Java, C++, JavaScript, C#, Go, Ruby.
392. Is Subsequence Python, Java, C++, JavaScript, C#, Go, Ruby.
583. Delete Operation for Two Strings Python, Java, C++, JavaScript, C#, Go, Ruby.
72. Edit Distance Python, Java, C++, JavaScript, C#, Go, Ruby.

Hard Problems

3494. Find the Minimum Amount of Time to Brew Potions Python, Java, C++, JavaScript, C#, Go, Ruby.

Monotonic Stack

739. Daily Temperatures Python, Java, C++, JavaScript, C#, Go, Ruby.
496. Next Greater Element I Python, Java, C++, JavaScript, C#, Go, Ruby.
42. Trapping Rain Water Python, Java, C++, JavaScript, C#, Go, Ruby.
84. Largest Rectangle in Histogram Python, Java, C++, JavaScript, C#, Go, Ruby.

Graph Theory

797. All Paths From Source to Target Python, Java, C++, JavaScript, C#, Go, Ruby, 2 approaches.
200. Number of Islands Python, Java, C++, JavaScript, C#, Go, Ruby, 3 approaches.
463. Island Perimeter Python, 2 approaches.
695. Max Area of Island Python, Java, C++, JavaScript, C#, Go, Ruby, 3 approaches.
827. Making A Large Island Python, 2 approaches.
127. Word Ladder Python.
1971. Find if Path Exists in Graph Python, Java, C++, JavaScript, C#, Go, Ruby, 2 approaches.
684. Redundant Connection Python, Java, C++, JavaScript, C#, Go, Ruby.
685. Redundant Connection II Python.
1584. Min Cost to Connect All Points Python, Java, C++, JavaScript, C#, Go, Ruby, 2 approaches.
207. Course Schedule Python, Java, C++, C#, 2 approaches.
1514. Path with Maximum Probability Python, 2 approaches.
752. Open the Lock Python, 2 approaches.
743. Network Delay Time Python, 2 approaches.
787. Cheapest Flights Within K Stops Python.
1334. Find the City With the Smallest Number of Neighbors at a Threshold Distance Python.

Other Algorithms

433. Minimum Genetic Mutation Python, 3 approaches.