HackerRank Python Solutions

A collection of Python solutions for various HackerRank programming challenges, covering fundamental algorithms, data structures, and Python-specific concepts.

🚀 Quick Start

# Run any solution
python <filename>.py

# Run tests (where available)
python test_<filename>.py

📁 Problem Categories

Collections Module

• py-collections-deque.py - Double-ended queue operations
• py-collections-namedtuple.py - Named tuple usage
• py-collections-ordereddict.py - Ordered dictionary implementation

Set Operations

• py-set-add.py - Adding elements to sets
• py-set-difference-operation.py - Set difference operations
• py-set-discard-remove-pop.py - Set element removal methods
• py-set-intersection-operation.py - Set intersection operations
• py-set-mutations.py - Set mutation operations
• py-set-symmetric-difference-operation.py - Symmetric difference operations
• py-set-union.py - Set union operations

String Manipulation

• py-ginorts.py - Custom string sorting with specific rules
• py-word-order.py - Word ordering and frequency analysis
• py-most-commons.py - Finding most common characters

Basic Python

• python-arithmetic-operators.py - Basic arithmetic operations
• python-division.py - Division operations
• python-loops.py - Loop constructs
• python-print.py - Print statement variations
• write-a-function.py - Function definition and leap year logic

Logic & Algorithms

• py-if-else.py - Conditional logic
• py-piling-up.py - Stack-based problem solving
• py-the-captains-room.py - Finding unique elements

🧪 Testing

Some solutions include comprehensive unit tests:

• test_py_ginorts.py - Complete test suite for the ginorts string sorting problem

Tests cover:

• Basic functionality
• Edge cases (empty inputs, single characters)
• Error handling
• Performance with large inputs

🛠️ Development

Code Structure

• Each file is a standalone solution
• Input/output handled via input() and print()
• Main execution in if __name__ == '__main__': blocks
• Modular functions for complex problems

Testing Framework

• Uses Python's built-in unittest module
• Comprehensive test coverage including edge cases
• Performance testing for larger inputs

📝 Solution Highlights

Advanced String Sorting (py-ginorts.py)

Implements custom sorting with specific rules:

1. Lowercase letters (alphabetically)
2. Uppercase letters (alphabetically)
3. Odd digits (numerically)
4. Even digits (numerically)

Collections Mastery

Demonstrates proper usage of Python's collections module:

• deque for efficient append/pop operations
• Counter for frequency analysis
• OrderedDict for maintaining insertion order

🎯 Problem-Solving Approach

1. Input Processing - Robust input handling and validation
2. Algorithm Implementation - Clean, readable solution logic
3. Edge Case Handling - Comprehensive coverage of boundary conditions
4. Testing - Unit tests where complexity warrants verification

🔧 Requirements

• Python 3.x
• No external dependencies (uses standard library only)

📚 Learning Resources

These solutions demonstrate key Python concepts:

• Lambda functions and custom sorting
• Collections module usage
• String manipulation techniques
• Set operations and mathematical concepts
• Error handling and input validation