my-leetcode-solution

my leetcode solution

做夠以下五項就可以開始technical interviews

1. Data Structure and algorithm: Leetcode 或 hackerrank 有免費offer依啲基本野 2）做common patterns: https://leetcode.com/discuss/interview-question/448285/List-of-questions-sorted-by-common-patterns. 3A) 開始瘋狂cold or warm call recruiters 3B) Object Oriented Design
2. System Design
3. Mock interviews

Leetcode Topic

• Sum
• Arrays & HashMap / HashTable
• Stack & Queue
• Linked list
• Search & Binary search
• Trees
• Graphs
• Backtracking
• Greedy
• Intervals
• Dynamic programming
• String & Palindrome
• Math, Matrix and Geometry
• Game theory

Important and Useful links from all over the LeetCode

Important and Useful links from all over the LeetCode - LeetCode Discuss

Formatting your posts in LeetCode :

1. Format Your Posts with Markdown

Dynamic Programming :

1. DP for Beginners [Problems | Patterns | Sample Solutions] by @wh0ami
2. DP Patterns by @aatalyk
3. How to solve DP - String? Template and 4 Steps to be followed by @igooglethings
4. Dynamic Programming Questions thread by @karansingh1559
5. DP Classification helpful notes by @adityakrverma
6. How to approach DP problems by @heroes3001
7. Iterative DP for subset sum problems by @yuxiangmusic
8. DP problems summary (problem categorization) by @richenyunqi
9. Categorization of Leetcode DP problems by @chuka231
10. Must do Dynamic Programming Category wise by @mahesh_nagarwal
11. Dynamic programming is simple by @omgitspavel

Backtracking :

1. Backtracking Summary and general template to solve many problems by @dichen001
2. A general approach to backtracking problems in C++ by @nitinpaldev
3. A general approach to backtracking problems in Java by @issac3

General Strategies and advice :

1. Comprehensive Data Structure and Algorithm Study Guide by @xrssa
2. Interview prep tips by @topcat

System Design

1. System Design template by @topcat
2. Design Facebook by @a_ranjan_s
3. Design URL Shortening service like TinyURL by @shashibk11
4. Design video sharing platform like Youtube by @Shuatify
5. System Design: Designing a distributed Job Scheduler | Many interesting concepts to learn (Leetcode's pick) by @sjkm
6. Whatsapp system design by @khushi511
7. System Design: Introduction to Distributed Systems | Designing a highly available system(Leetcode's pick) by @Vruttant1403
8. System Design questions asked in FAANG

How to use LeetCode :

1. A must-read guide for new LeetCode users by @LeetCode
2. How to use Leetcode efficiently and effectively by beginners by @megaspazz
3. How to effectively use LeetCode to prepare for interviews!! by @Pooja0406
4. Interview preparation study plan using leetcode (Leetcode's pick) by @amit_gupta10

Important list of questions :

1. List of questions sorted by common patterns by @Maverick2594
2. Topic wise problems for beginners by @yashrsharma44
3. Facebook interview question list by @suresh_reddy

Graphs and Trees :

1. Graph for beginners by @wh0ami
2. DFS for beginners by @StefanPochmann
3. Recursive approach to segment trees and range sum queries and lazy propagation
4. Article on Trie. General Template and List of problems by @igooglethings
5. Iterative and recursive versions of common tree problems by @nareshyoutube
6. Graph Algorithms One Place | Dijkstra | Bellman Ford | Floyd Warshall | Prims | Kruskals | DSU by @nareshyoutube
7. Disjoint Set Union (DSU)/Union-Find - A Complete Guide @Invulnerable
8. Introduction to Trie by @since2020
9. A noob's guide to Dijkstra's Algorithm (Leetcode's pick) by @bliss14b

Stacks and Queues :

1. Monotonic Queue Summary by @luxy622
2. Applications of Monotonous Increasing stack by @wxd_sjtu

Sliding Window :

1. Sliding window for beginners by @wh0ami
2. Sliding Window algorithm template to solve all the Leetcode substring search problem by @chaoyanghe

Binary Search :

1. Binary Search for Beginners by @wh0ami
2. [Python] Powerful Ultimate Binary Search Template. Solved many problems by @zhjiun_liao
3. Binary Search 101 by @AminiCK

Approaches to deal with problems which follow some pattern :

1. Most consistent ways of dealing with the series of stock problems by @fun4LeetCode
2. Sum Megapost (How to solve 2 sum, 3 sum and 4 sum) by @peyman_np
3. How to solve linked list problems in C++ by @LHearen
4. Template for all combination problem set by @fight.for.dream
5. Summary of solutions for problems "reducible" to LeetCode 378 (Kth smallest element in a sorted matrix) by @fun4LeetCode

Bit manipulation :

1. Using bit manipulation to solve problems easily and efficiently by @LHearen
2. All about Bitwise Operations Beginner Intermediate by @Yashjain

Greedy :

1. Greedy for beginners by @wh0ami
2. ABCs of Greedy by Sapphire_Skies

Two pointers :

1. General summary of what kind of problem can/ cannot solved by Two Pointers by @a2232189

想操leetcode 的人可以由依個75 questions開始

https://www.teamblind.com/post/New-Year-Gift---Curated-List-of-Top-75-LeetCode-Questions-to-Save-Your-Time-OaM1orEU

Blind 75 questions

Array

• Two Sum - https://leetcode.com/problems/two-sum/
• Best Time to Buy and Sell Stock - https://leetcode.com/problems/best-time-to-buy-and-sell-stock/
• Contains Duplicate - https://leetcode.com/problems/contains-duplicate/
• Product of Array Except Self - https://leetcode.com/problems/product-of-array-except-self/
• Maximum Subarray - https://leetcode.com/problems/maximum-subarray/
• Maximum Product Subarray - https://leetcode.com/problems/maximum-product-subarray/
• Find Minimum in Rotated Sorted Array - https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/
• Search in Rotated Sorted Array - https://leetcode.com/problems/search-in-rotated-sorted-array/
• 3Sum - https://leetcode.com/problems/3sum/
• Container With Most Water - https://leetcode.com/problems/container-with-most-water/

Binary

• Sum of Two Integers - https://leetcode.com/problems/sum-of-two-integers/
• Number of 1 Bits - https://leetcode.com/problems/number-of-1-bits/
• Counting Bits - https://leetcode.com/problems/counting-bits/
• Missing Number - https://leetcode.com/problems/missing-number/
• Reverse Bits - https://leetcode.com/problems/reverse-bits/

Dynamic Programming

• Climbing Stairs - https://leetcode.com/problems/climbing-stairs/
• Coin Change - https://leetcode.com/problems/coin-change/
• Longest Increasing Subsequence - https://leetcode.com/problems/longest-increasing-subsequence/
• Longest Common Subsequence -
• Word Break Problem - https://leetcode.com/problems/word-break/
• Combination Sum - https://leetcode.com/problems/combination-sum-iv/
• House Robber - https://leetcode.com/problems/house-robber/
• House Robber II - https://leetcode.com/problems/house-robber-ii/
• Decode Ways - https://leetcode.com/problems/decode-ways/
• Unique Paths - https://leetcode.com/problems/unique-paths/
• Jump Game - https://leetcode.com/problems/jump-game/

Graph

• Clone Graph - https://leetcode.com/problems/clone-graph/
• Course Schedule - https://leetcode.com/problems/course-schedule/
• Pacific Atlantic Water Flow - https://leetcode.com/problems/pacific-atlantic-water-flow/
• Number of Islands - https://leetcode.com/problems/number-of-islands/
• Longest Consecutive Sequence - https://leetcode.com/problems/longest-consecutive-sequence/
• Alien Dictionary (Leetcode Premium) - https://leetcode.com/problems/alien-dictionary/
• Graph Valid Tree (Leetcode Premium) - https://leetcode.com/problems/graph-valid-tree/
• Number of Connected Components in an Undirected Graph (Leetcode Premium) - https://leetcode.com/problems/number-of-connected-components-in-an-undirected-graph/

Interval

• Insert Interval - https://leetcode.com/problems/insert-interval/
• Merge Intervals - https://leetcode.com/problems/merge-intervals/
• Non-overlapping Intervals - https://leetcode.com/problems/non-overlapping-intervals/
• Meeting Rooms (Leetcode Premium) - https://leetcode.com/problems/meeting-rooms/
• Meeting Rooms II (Leetcode Premium) - https://leetcode.com/problems/meeting-rooms-ii/

Linked List

• Reverse a Linked List - https://leetcode.com/problems/reverse-linked-list/
• Detect Cycle in a Linked List - https://leetcode.com/problems/linked-list-cycle/
• Merge Two Sorted Lists - https://leetcode.com/problems/merge-two-sorted-lists/
• Merge K Sorted Lists - https://leetcode.com/problems/merge-k-sorted-lists/
• Remove Nth Node From End Of List - https://leetcode.com/problems/remove-nth-node-from-end-of-list/
• Reorder List - https://leetcode.com/problems/reorder-list/

Matrix

• Set Matrix Zeroes - https://leetcode.com/problems/set-matrix-zeroes/
• Spiral Matrix - https://leetcode.com/problems/spiral-matrix/
• Rotate Image - https://leetcode.com/problems/rotate-image/
• Word Search - https://leetcode.com/problems/word-search/

String

• Longest Substring Without Repeating Characters - https://leetcode.com/problems/longest-substring-without-repeating-characters/
• Longest Repeating Character Replacement - https://leetcode.com/problems/longest-repeating-character-replacement/
• Minimum Window Substring - https://leetcode.com/problems/minimum-window-substring/
• Valid Anagram - https://leetcode.com/problems/valid-anagram/
• Group Anagrams - https://leetcode.com/problems/group-anagrams/
• Valid Parentheses - https://leetcode.com/problems/valid-parentheses/
• Valid Palindrome - https://leetcode.com/problems/valid-palindrome/
• Longest Palindromic Substring - https://leetcode.com/problems/longest-palindromic-substring/
• Palindromic Substrings - https://leetcode.com/problems/palindromic-substrings/
• Encode and Decode Strings (Leetcode Premium) - https://leetcode.com/problems/encode-and-decode-strings/

Tree

• Maximum Depth of Binary Tree - https://leetcode.com/problems/maximum-depth-of-binary-tree/
• Same Tree - https://leetcode.com/problems/same-tree/
• Invert/Flip Binary Tree - https://leetcode.com/problems/invert-binary-tree/
• Binary Tree Maximum Path Sum - https://leetcode.com/problems/binary-tree-maximum-path-sum/
• Binary Tree Level Order Traversal - https://leetcode.com/problems/binary-tree-level-order-traversal/
• Serialize and Deserialize Binary Tree - https://leetcode.com/problems/serialize-and-deserialize-binary-tree/
• Subtree of Another Tree - https://leetcode.com/problems/subtree-of-another-tree/
• Construct Binary Tree from Preorder and Inorder Traversal - https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/
• Validate Binary Search Tree - https://leetcode.com/problems/validate-binary-search-tree/
• Kth Smallest Element in a BST - https://leetcode.com/problems/kth-smallest-element-in-a-bst/
• Lowest Common Ancestor of BST - https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/
• Implement Trie (Prefix Tree) - https://leetcode.com/problems/implement-trie-prefix-tree/
• Add and Search Word - https://leetcode.com/problems/add-and-search-word-data-structure-design/
• Word Search II - https://leetcode.com/problems/word-search-ii/

Heap

• Merge K Sorted Lists - https://leetcode.com/problems/merge-k-sorted-lists/
• Top K Frequent Elements - https://leetcode.com/problems/top-k-frequent-elements/
• Find Median from Data Stream - https://leetcode.com/problems/find-median-from-data-stream/

A LeetCode list for each of the patterns

• 2 Heaps
• Arrays
• Backtracking
• Dynamic Programming
• Fast & Slow pointers
• Graph Traversal
• In-place traversal of LL
• K-way merge
• Merge Intervals
• Modified Binary Search
• Sliding window
• Top K elements
• Topological Sorting
• Tree BFS
• Tree DFS
• Two Pointers