This PR transforms the minimal repository into a comprehensive Java coding test preparation framework, implementing fundamental algorithms and data structures commonly used in technical interviews.

What's Added

Core Algorithm Classes

• CodingTest.java - Main demonstration class showcasing all implemented algorithms
• ArrayProblems.java - Array manipulation algorithms including:
  • Find maximum/minimum elements (O(n))
  • Bubble sort implementation (O(n²))
  • Two Sum problem solver (O(n²))
  • Array reversal in-place (O(n))
• StringProblems.java - String processing algorithms including:
  • String reversal (O(n))
  • Palindrome detection (O(n))
  • Anagram checking (O(n log n))
  • First non-repeating character finder (O(n))
  • Vowel counting (O(n))
• SearchAlgorithms.java - Search implementations including:
  • Linear search (O(n))
  • Binary search iterative and recursive (O(log n))
  • First/last occurrence in sorted arrays (O(log n))

Testing & Documentation

• AlgorithmTest.java - Comprehensive test suite with 14 tests achieving 100% success rate
• Updated README.md - Detailed documentation with usage instructions, complexity analysis, and examples
• .gitignore - Standard Java project exclusions

Demo Output

When running the main class, users see practical demonstrations:

=== Coding Test Algorithms Demo ===

1. Array Problems:
Original array: [3, 1, 4, 1, 5, 9, 2, 6]
Max element: 9
Sorted array: [1, 1, 2, 3, 4, 5, 6, 9]

2. String Problems:
Original string: hello
Reversed: olleh
Is palindrome 'racecar': true

3. Search Algorithms:
Array: [1, 3, 5, 7, 9, 11, 13, 15]
Linear search for 7: 3
Binary search for 7: 3

Verification

All implementations have been thoroughly tested:

• Code compiles successfully with javac
• Main demo runs without errors
• Test suite passes all 14 tests with 100% success rate
• Each algorithm includes detailed time and space complexity documentation

This provides a solid foundation for coding interview preparation with implementations of the most commonly asked algorithmic problems.

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