Practice

This is a humble personal repo of practice coding exercises. It might be helpful for advanced beginners or working developers who need to brush up on the basics.

Getting started

Clone this repo and run mvn test.

Using the code:

• Pick a file to work on in the src/main/java/io/github/twblamer/practice/exercises directory (e.g. LinkedListExercises.java)
• Pick a method to work on, comment out the line that calls the existing solution, and write your own solution.
• Run mvn test to check your work. (Or use the test runner in your IDE)

Resources

Courses

• Open Source Society University

Interview Prep

• Leetcode solutions (@cheonhyangzhang)
• NeetCode.io

Roadmaps

• Baeldung CS Tutorials (baeldung.com)
• Coding Interview University (@jwasham) - Extremely thorough and opinionated guide, better suited for absolute beginners
• Complete Roadmap To Learn DSA From Scratch (geeksforgeeks.org)
• Computer Science Roadmap (roadmap.sh) ⭐
• Teach Yourself Computer Science (teachyourselfcs.com)

Textbooks

• Algorithms, 4th Edition (Sedgewick/Wayne)

YouTube

• Good for binge watching
  • Algorithms with Attitude
  • [HackerRank] Algorithms
  • [HackerRank] Data Structures
  • Michael Sambol ⭐
  • [NeetCode] LeetCode BLIND-75 Solutions
• Full course lectures
  • MIT 6.006 Introduction to Algorithms, Spring 2020
  • Stony Brook University CSE 373 Analysis of Algorithms, Fall 2020

Links by Topic

• Arrays
  • [NeetCode] Binary Search - Leetcode 704
  • [NeetCode] Majority Element - Leetcode 169
  • [NeetCode] Maximum Subarray - Leetcode 53
  • [NeetCode] Maximum Product Subarray - Leetcode 152
  • [Wikipedia] Boyer–Moore majority vote algorithm
  • [Wikipedia] Maximum subarray problem
• Binary Tree
  • [NeetCode] Binary Search Tree Iterator - Leetcode 173
  • [NeetCode] Binary Tree Level Order Traversal - Leetcode 102
  • [NeetCode] Binary Tree Postorder Traversal (Iterative) - Leetcode 145
  • [NeetCode] Binary Tree Preorder Traversal (Iterative) - Leetcode 144
  • [NeetCode] Convert Sorted Array to Binary Search Tree - Leetcode 108
  • [NeetCode] Invert Binary Tree - Leetcode 226
  • [NeetCode] Iterative & Recursive - Binary Tree Inorder Traversal - Leetcode 94
  • [Sedgewick/Wayne] Binary Search Trees
• Bit Manipulation
  • bitwise | Alexandra Zaharia
  • [GeeksforGeeks] Bit Tricks for Competitive Programming
  • [HackerRank] Algorithms: Bit Manipulation
• Graph
  • Directed Graph
    • [Algorithms with Attitude] Kosaraju's Algorithm for Strongly Connected Components
    • [Sedgewick/Wayne] Directed Graphs
  • Graph Traversal
    • [Algorithms with Attitude] Graphs: Breadth First Search (BFS) with Example
    • [Algorithms with Attitude] Graphs: Depth First Search (DFS) with Example
    • [Spanning Tree] How Dijkstra's Algorithm Works
  • Topological Sort
    • [Algorithms with Attitude] Introduction to Topological Sorting in Directed Acyclic Graphs
    • [Algorithms with Attitude] Kahn's Algorithm for Topological Sorting
    • [Algorithms with Attitude] Depth First Search Based Topological Sort
    • [Baeldung] Topological Sort of Directed Acyclic Graph
    • [NeetCode] Alien Dictionary - Topological Sort - Leetcode 269
    • [Wikipedia] Topological sorting
  • Undirected Graph
    • [Sedgewick/Wayne] Undirected Graphs
• Hash Table
  • [HackerRank] Data Structures: Hash Tables
  • [NeetCode] Design Hashmap - Leetcode 706
  • [Sedgewick/Wayne] Hash Tables
• Heap
  • [Algorithms with Attitude] Introduction to Binary Heaps
  • [Algorithms with Attitude] Linear Time BuildHeap
  • [HackerRank] Data Structures: Heaps
  • [NeetCode] Find Median from Data Stream - Leetcode 295
  • [Wikipedia] Binary heap
• Linked List
  • [NeetCode] Reverse Linked List - Leetcode 206
• Sorting Algorithms
  • Insertion Sort
    • [NeetCode] Insertion Sort List - Leetcode 147
    • [Sedgewick/Wayne] Elementary Sorts
  • Mergesort
    • [Algorithms with Attitude] Merge Sort: Top-Down and Bottom-Up
    • [Curious Walk] Merge Sort | Manim Animation
    • [HackerRank] Algorithms: Merge Sort
    • [Sedgewick/Wayne] Mergesort
  • Quicksort
    • [Algorithms with Attitude] Quick Sort and Quick Select
    • [Curious Walk] Quick Sort | Manim Animation
    • [GeeksforGeeks] Hoare’s vs Lomuto partition scheme in QuickSort
    • [HackerRank] Algorithms: Quicksort
    • [NeetCode] Sort Colors - Quicksort Partition - Leetcode 75
    • [Sedgewick/Wayne] Quicksort
    • [Techie Delight] Quicksort Algorithm
    • [Wikipedia] Median of medians
    • [Wikipedia] Quickselect
• Trie
  • [HackerRank] Data Structures: Tries
  • [Sedgewick/Wayne] Tries
  • [Wikipedia] Trie