Java Data Structures & Algorithms

A comprehensive collection of data structures and algorithms implemented in Java, designed for learning, practice, and interview preparation.

📚 Data Structures

Trees

• Binary Trees: Implementation with preorder, inorder, postorder, and level-order traversals
• Binary Search Trees: Building, searching, deletion, and validation
• Tree Operations: Height calculation, diameter finding, lowest common ancestor, kth ancestor

Graphs

• Edge and Vertex representation
• Graph Algorithms:
  • Dijkstra's Algorithm for shortest paths
  • Prim's Algorithm for minimum spanning trees
  • Bellman-Ford Algorithm for detecting negative cycles
  • Topological Sorting for directed acyclic graphs

LinkedLists

• Node implementation with operations
• Operations: Reversing, cycle detection and removal
• Pattern operations: Delete N nodes after M nodes
• Palindrome checking in linked lists

Heaps

• Priority Queue implementation
• Operations for finding maximum element in k-sized subarrays

Tries

• Character-based tree for efficient string operations
• Prefix searching and insertion
• Word finding algorithms

Arrays & ArrayLists

• Stock buying and selling algorithms
• 2D array operations
• Random array generation utilities

🧮 Algorithms

Searching & Sorting

• Binary Search implementations
• Various sorting techniques

Dynamic Programming

• Solutions to common DP problems

Bit Manipulation

• Operations: Get, Set, Clear, and Update bits
• Bit counting and power of 2 checking
• Fast exponentiation using bit operations

Backtracking

• Solutions to classic backtracking problems

Greedy Algorithms

• Optimization problems with greedy approaches

🛠️ Utilities

Random Data Generation

• Methods for generating test data:
  • Integer arrays (1D and 2D)
  • String arrays with case control
  • Character arrays
  • Boolean arrays
  • Specialized data structures

Testing Framework

• LeetCodeTestBench for rapid algorithm testing
• Performance timing measurements

📋 Usage

The code is organized into individual class files for each data structure or algorithm type. Each file contains multiple implementations and example usage in their respective main() methods.

🎯 Learning Resources

This repository is designed to complement standard algorithm and data structure courses. Each implementation includes detailed comments explaining the time and space complexity analysis.