Push_swap

Push_swap is a sorting algorithm project in C, designed to sort data on a stack using a limited set of operations. The main goal of this project is to sort a stack of integers with the minimum number of operations and to understand and implement sorting algorithms.

Table of Contents

• Introduction
• How It Works
• Installation
• Usage
• Operations
• Example
• Resources
• License

Introduction

The Push_swap project is part of the 42 curriculum and is designed to improve your algorithmic skills, especially regarding sorting algorithms and manipulation of stacks. The goal is to sort a stack using a set of predefined operations while minimizing the number of moves.

How It Works

The project consists of two main components:

1. Push_swap Program: This program calculates and outputs the list of operations needed to sort the stack of integers.
2. Checker Program: This program validates if the stack is correctly sorted using the provided operations.

The allowed operations are a set of basic operations on two stacks (stack a and stack b). You need to implement these operations and combine them efficiently to sort the stack with the minimum number of moves.

Installation

To install and build the project, follow these steps:

1. Clone the repository:

   git clone https://github.com/jternero/push_swap.git
   cd push_swap

2. Build the project:

   make

This will compile the push_swap and checker programs.

Usage

Running the push_swap Program

You can run the push_swap program to generate the operations needed to sort a stack:

./push_swap [numbers]

• Example:

  ./push_swap 4 3 2 1

This will output the operations required to sort the stack [4, 3, 2, 1].

Running the checker Program

You can validate your sorting operations using the checker program:

./checker [numbers]

After running checker, you can input the operations manually or use the output of push_swap:

./push_swap 4 3 2 1 | ./checker 4 3 2 1

This will verify if the operations provided by push_swap correctly sort the stack. The checker will output OK if the stack is sorted, or KO if not.

Operations

The following operations are allowed:

• sa: Swap the first two elements of stack a.
• sb: Swap the first two elements of stack b.
• ss: Perform sa and sb simultaneously.
• pa: Push the first element from stack b onto stack a.
• pb: Push the first element from stack a onto stack b.
• ra: Rotate stack a (move the first element to the end).
• rb: Rotate stack b.
• rr: Perform ra and rb simultaneously.
• rra: Reverse rotate stack a (move the last element to the beginning).
• rrb: Reverse rotate stack b.
• rrr: Perform rra and rrb simultaneously.

Example

$ ./push_swap 3 2 1
sa
ra

This example shows the output of push_swap for sorting the stack [3, 2, 1]. The operations sa and ra will sort the stack in ascending order.

You can verify it with the checker:

$ ./push_swap 3 2 1 | ./checker 3 2 1
OK

Resources

For more information on the Push_swap project and how to implement efficient sorting algorithms, you can refer to:

• 42 School Push_swap Subject
• Sorting Algorithms

License

This project is licensed under the MIT License - see the LICENSE file for details.