Dear LeetCoders! For a better LeetCode problem-solving experience, please visit website leetcoder.net: Dare to claim the best practices of LeetCode solutions! Will save you a lot of time!
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!
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.
- 344. Reverse String was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 27. Remove Element was solved in Python, Java, C++, JavaScript, C#, Go, Ruby and 2 ways.
- 704. Binary Search was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 977. Squares of a Sorted Array was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 209. Minimum Size Subarray Sum was solved in Python, Java, C++, JavaScript, C#, Go, Ruby#.
- 303. Range Sum Query - Immutable was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 59. Spiral Matrix II was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 503. Next Greater Element II was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 3478. Choose K Elements With Maximum Sum was solved in Python.
- 203. Remove Linked List Elements was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 206. Reverse Linked List was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 160. Intersection of Two Linked Lists was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 19. Remove Nth Node From End of List was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 707. Design Linked List was solved in Python, Java, C++, JavaScript, C#, Go, Ruby#.
- 24. Swap Nodes in Pairs was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 349. Intersection of Two Arrays was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 242. Valid Anagram was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 1. Two Sum was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 383. Ransom Note was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 202. Happy Number was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 454. 4Sum II was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 49. Group Anagrams was solved in Python, Ruby.
- 28. Find the Index of the First Occurrence in a String was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 541. Reverse String II was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 459. Repeated Substring Pattern was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 833. Find And Replace in String was solved in Python.
- 15. 3Sum was solved in Python, Java, C++, JavaScript, C#, Go, Ruby and 2 ways.
- 18. 4Sum was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 20. Valid Parentheses was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 232. Implement Queue using Stacks was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 225. Implement Stack using Queues was solved in Python, Java, C++, JavaScript, C#, Go, Ruby and 3 ways.
- 144. Binary Tree Preorder Traversal was solved in Python and 2 ways.
- 509. Fibonacci Number was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 198. House Robber was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 213. House Robber II was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 337. House Robber III was solved in Python, Java, C++, JavaScript, C#, Go, Ruby and 2 ways.
- 416. Partition Equal Subset Sum was solved in Python, Java, C++, JavaScript, C#, Go, Ruby and 2 ways.
- 1049. Last Stone Weight II was solved in Python, Java, C++, JavaScript, C#, Go, Ruby and 2 ways.
- 494. Target Sum was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 474. Ones and Zeroes was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 518. Coin Change II was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 377. Combination Sum IV was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 322. Coin Change was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 279. Perfect Squares was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 139. Word Break was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 121. Best Time to Buy and Sell Stock was solved in Python, JavaScript, Go.
- 122. Best Time to Buy and Sell Stock II was solved in Python, JavaScript, Go.
- 714. Best Time to Buy and Sell Stock with Transaction Fee was solved in Python, JavaScript, Go.
- 123. Best Time to Buy and Sell Stock III was solved in Python, JavaScript, Go.
- 188. Best Time to Buy and Sell Stock IV was solved in Python, JavaScript, Go.
- 309. Best Time to Buy and Sell Stock with Cooldown was solved in Python, JavaScript, Go.
- 674. Longest Continuous Increasing Subsequence was solved in Python, Java, JavaScript, C#.
- 300. Longest Increasing Subsequence was solved in Python, Java, JavaScript, C#.
- 718. Maximum Length of Repeated Subarray was solved in Python, Java, JavaScript, C#.
- 1143. Longest Common Subsequence was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 1035. Uncrossed Lines was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 53. Maximum Subarray was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 392. Is Subsequence was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 583. Delete Operation for Two Strings was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 72. Edit Distance was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 3494. Find the Minimum Amount of Time to Brew Potions was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 739. Daily Temperatures was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 496. Next Greater Element I was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 42. Trapping Rain Water was solved in _Python, Java, C++, JavaScript, C#, Go, Ruby.
- 84. Largest Rectangle in Histogram was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 797. All Paths From Source to Target was solved in Python, Java, C++, JavaScript, C#, Go, Ruby and 2 ways.
- 200. Number of Islands was solved in Python, Java, C++, JavaScript, C#, Go, Ruby and 3 ways.
- 463. Island Perimeter was solved in Python and 2 ways.
- 695. Max Area of Island was solved in Python, Java, C++, JavaScript, C#, Go, Ruby and 3 ways.
- 827. Making A Large Island was solved in Python and 2 ways.
- 127. Word Ladder was solved in Python.
- 1971. Find if Path Exists in Graph was solved in Python, Java, C++, JavaScript, C#, Go, Ruby and 2 ways.
- 684. Redundant Connection was solved in Python, Java, C++, JavaScript, C#, Go, Ruby.
- 685. Redundant Connection II was solved in Python.
- 1584. Min Cost to Connect All Points was solved in Python, Java, C++, JavaScript, C#, Go, Ruby and 2 ways.
- 207. Course Schedule was solved in Python, Java, C++, C# and 2 ways.
- 1514. Path with Maximum Probability was solved in Python and 2 ways.
- 752. Open the Lock was solved in Python and 2 ways.
- 743. Network Delay Time was solved in Python and 2 ways.
- 787. Cheapest Flights Within K Stops was solved in Python.
- 1334. Find the City With the Smallest Number of Neighbors at a Threshold Distance was solved in Python.
- 433. Minimum Genetic Mutation was solved in Python and 3 ways.
More LeetCode problems will be added soon.