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CSES

This repo contains personal validated answers to the CSES online platform questions about competitive programming.

Overview

CSES is a collection of solutions to competitive programming problems from the CSES Problem Set (cses.fi). Each file contains a validated, accepted solution to a specific problem, demonstrating efficient algorithms and problem-solving techniques in C.

How It Works

The repository contains individual C files, each solving a distinct CSES problem:

weirdAlgorithm.c: Solution to the Weird Algorithm problem

// Implements the Collatz conjecture sequence

missing.c: Solution to the Missing Number problem

// Finds the missing number in a sequence from 1 to n

moves.c: Solution to a moves-based problem

// Calculates optimal moves or sequences

dna.c: Solution to a DNA sequence problem

// Processes and analyzes DNA string patterns

Core Functionality

1. Competitive Programming Solutions: Each file solves a specific algorithmic challenge
2. Optimized Code: Solutions are written to pass CSES time and memory constraints
3. Standard Input/Output: Programs read from stdin and write to stdout as per CSES format
4. Validated Answers: All solutions have been accepted by the CSES platform

Problem-Solving Approach

When tackling a CSES problem:

1. Understand the problem constraints and requirements
2. Design an efficient algorithm (often O(n) or O(n log n))
3. Implement the solution in C with careful memory management
4. Test with sample inputs and edge cases
5. Submit to CSES and validate acceptance

Key Concepts Demonstrated

• Algorithm Design: Efficient solutions to classic competitive programming problems
• C Programming: Low-level control, pointers, and memory management
• Time Complexity: Optimizing for speed to meet strict time limits
• Standard I/O: Fast input/output handling for large datasets
• Problem Decomposition: Breaking complex problems into manageable steps

Installation

1. Clone the repository:

git clone https://github.com/achille010/cses.git
cd cses

2. Compile a solution:

gcc -o weirdAlgorithm weirdAlgorithm.c

3. Run the executable:

./weirdAlgorithm

4. Or compile with optimization flags:

gcc -O2 -o weirdAlgorithm weirdAlgorithm.c

Usage Examples

Weird Algorithm

# Input: 3
# Output: 3 10 5 16 8 4 2 1

Missing Number

# Input: n=5, numbers: 1 2 4 5
# Output: 3

Limitations

• Solutions are problem-specific and not generalized
• No test cases included in the repository
• Assumes familiarity with CSES problem statements
• Code is optimized for correctness and speed, not necessarily readability

This is intentionally focused on competitive programming solutions for the CSES platform.

Requirements

• C compiler (gcc, clang, or similar)
• Basic understanding of algorithms and data structures
• Access to CSES problem set for problem statements

Contributing

Contributions are welcome! Feel free to fork this repository and submit pull requests for improvements.

License

MIT License - Read details from the LICENSE file

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Built as a collection of validated CSES competitive programming solutions