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Abhijeet Giri edited this page Feb 28, 2026 · 1 revision

Perfect, Abhijeet 🔥
Here’s a more detailed, structured, and professional Wiki Home Page for your Data-Structures-and-Algorithms-Java repository.

You can directly paste this into your GitHub Wiki home page.

📘 Data-Structures-and-Algorithms-Java Wiki

Welcome to the official documentation of Data-Structures-and-Algorithms-Java 🚀

This repository is a comprehensive and structured collection of Data Structures and Algorithms implemented in Java, designed for:

  • 🎯 Technical Interview Preparation

  • 🏆 Competitive Programming

  • 🧠 Problem-Solving Mastery

  • 🎓 Academic Coursework

  • 💼 Placement Preparation

📚 Table of Contents

  1. 📌 Repository Overview

  2. 🗂 Folder Structure

  3. 🧮 Time & Space Complexity Guide

  4. 🔍 Searching Algorithms

  5. 🔄 Sorting Algorithms

  6. 🧱 Core Data Structures

  7. 🧠 Recursion & Backtracking

  8. 🌳 Trees

  9. 🌐 Graphs

  10. ⚡ Dynamic Programming

  11. 🧪 Coding Standards

  12. 🏷 Problem Classification System

  13. 🎯 Interview Preparation Roadmap

  14. 🤝 Contribution Guidelines

📌 Repository Overview

This project focuses on:

  • Clean Java implementations

  • Beginner-friendly logic

  • Step-by-step algorithm explanation

  • Proper documentation & comments

  • Optimized approaches

  • Interview-focused patterns

Each program contains:

  • ✔️ Problem Statement

  • ✔️ Algorithm Explanation

  • ✔️ Time Complexity

  • ✔️ Space Complexity

  • ✔️ Edge Case Handling

  • ✔️ Clean Output Formatting

🗂 Folder Structure

Data-Structures-and-Algorithms-Java/
│
├── Searching/
│   ├── LinearSearch.java
│   ├── BinarySearch.java
│   └── Variations/
│
├── Sorting/
│   ├── BubbleSort.java
│   ├── SelectionSort.java
│   ├── InsertionSort.java
│   ├── MergeSort.java
│   └── QuickSort.java
│
├── Recursion/
│
├── LinkedList/
│
├── Stack/
│
├── Queue/
│
├── Trees/
│
├── Graphs/
│
├── DynamicProgramming/
│
└── utils/
    └── InputHelper.java

🧮 Time & Space Complexity Cheat Sheet

Operation | Best | Average | Worst -- | -- | -- | -- Linear Search | O(1) | O(n) | O(n) Binary Search | O(1) | O(log n) | O(log n) Bubble Sort | O(n) | O(n²) | O(n²) Merge Sort | O(n log n) | O(n log n) | O(n log n) Quick Sort | O(n log n) | O(n log n) | O(n²)

🔍 Searching Algorithms

1️⃣ Linear Search

  • Iterative search

  • Works on unsorted arrays

  • Time Complexity: O(n)

2️⃣ Binary Search

  • Works only on sorted arrays

  • Iterative & Recursive implementations

  • Time Complexity: O(log n)

  • Includes:

    • First Occurrence

    • Last Occurrence

    • Floor / Ceil

    • Rotated Array Search

🔄 Sorting Algorithms

1️⃣ Bubble Sort

  • Adjacent comparison

  • Stable

  • Easy to understand

2️⃣ Selection Sort

  • Select minimum element

  • Not stable

  • Fewer swaps

3️⃣ Insertion Sort

  • Best for small arrays

  • Adaptive

4️⃣ Merge Sort

  • Divide and Conquer

  • Stable

  • O(n log n)

5️⃣ Quick Sort

  • Divide and Conquer

  • In-place sorting

  • Fast in practice

🧱 Core Data Structures

Arrays

  • Traversal

  • Prefix Sum

  • Two Pointer Technique

  • Sliding Window

Linked List

  • Singly Linked List

  • Doubly Linked List

  • Reverse Linked List

  • Cycle Detection

Stack

  • Array implementation

  • LinkedList implementation

  • Balanced Parentheses

  • Next Greater Element

Queue

  • Circular Queue

  • Deque

  • Priority Queue

🌳 Trees

  • Binary Tree

  • Binary Search Tree

  • Tree Traversals:

    • Inorder

    • Preorder

    • Postorder

    • Level Order

  • Height / Diameter

  • Lowest Common Ancestor

  • AVL Tree (Planned)

🌐 Graphs

  • Graph Representation

    • Adjacency Matrix

    • Adjacency List

  • BFS

  • DFS

  • Cycle Detection

  • Topological Sort

  • Dijkstra's Algorithm

  • Minimum Spanning Tree (Planned)

⚡ Dynamic Programming (Upcoming Expansion)

  • Fibonacci

  • 0/1 Knapsack

  • Longest Common Subsequence

  • Longest Increasing Subsequence

  • Matrix Chain Multiplication

🧪 Coding Standards

This repository follows:

  • Meaningful variable names

  • Proper indentation

  • JavaDoc-style comments

  • Clear method separation

  • Modular code design

🏷 Problem Classification System

Each problem is tagged with:

  • 🟢 Easy

  • 🟡 Medium

  • 🔴 Hard

And categorized by:

  • Topic

  • Pattern

  • Company Frequency (Planned)

  • Interview Importance

🎯 8–12 Week Interview Preparation Roadmap

Week 1–2

  • Arrays & Strings

  • Basic Searching & Sorting

Week 3–4

  • Recursion

  • Backtracking

  • Linked List

Week 5–6

  • Stack & Queue

  • Hashing

Week 7–8

  • Trees

  • BST

  • Heap

Week 9–10

  • Graphs

Week 11–12

  • Dynamic Programming

🚀 Future Enhancements

  • 🔗 LeetCode problem mapping

  • 📊 Performance comparison benchmarks

  • 📄 PDF Notes

  • 🎥 Video explanations

  • 🧪 Unit tests

  • 🏗 Maven / Gradle build support

🤝 Contribution Guidelines

If you’d like to contribute:

  1. Fork the repository

  2. Create a feature branch

  3. Follow coding standards

  4. Add proper documentation

  5. Submit a pull request

👨‍💻 Maintainer

Abhijeet Giri
Java | DSA | Backend | Cloud

If you'd like next, I can generate:

  • 📘 Individual detailed wiki page for Merge Sort

  • 📊 Complexity visual explanation page

  • 🌳 Complete Trees theory page

  • 🌐 Complete Graph theory page

  • 🎯 FAANG-focused interview version of this wiki

Just tell me which one to build next 🚀

Clone this wiki locally