push_swap

An optimized stack-sorting program in C that outputs the minimal (or near-minimal) sequence of allowed operations to sort integers.

Overview

push_swap is a well-known 42 School project: given a list of integers, you must sort them using two stacks (A and B) and a limited set of stack operations, printing the operations to stdout.

This repo implements:

• parsing + validation (integers only, no duplicates, int range)
• stack representation and operations
• specialized strategies for small inputs (3/4/5)
• scalable strategies for larger sets (100/500), using indexing / chunking style approaches

Repository: otelliq/push_swap
Default branch: main

Tech stack

• C
• Makefile build
• Custom libft (vendored in push_swap/libft)

Key features

• Implements all required moves:
  • swaps: sa, sb, ss
  • pushes: pa, pb
  • rotates: ra, rb, rr
  • reverse rotates: rra, rrb, rrr
• Robust input validation:
  • checks digits / sign
  • prevents overflow (INT_MIN..INT_MAX)
  • detects duplicates
• Multiple sorting strategies:
  • sort_3, sort_4, sort_5
  • sort_100, sort_500 (and reverse variants)

(See function prototypes in push_swap/push_swap.h.)

Screenshots

No screenshots provided yet.

A good screenshot to add is a small run example showing the printed operations.

Installation & setup

Prerequisites

• make
• C compiler (cc / clang / gcc)

Build

From the repository root:

make -C push_swap

This should produce the push_swap executable (depending on Makefile rules).

Usage examples

Sort a list of numbers

./push_swap 3 2 1

Output will be a sequence of operations, e.g.:

sa
rra

Provide numbers as a single quoted string

If your parser supports it (common in 42 projects):

./push_swap "3 2 1 6 5"

Verify correctness (with a checker)

If you have a checker tool available (from 42 resources), you can pipe the operations:

ARG="4 67 3 87 23"; ./push_swap $ARG | ./checker $ARG

Project structure

.
└── push_swap/
    ├── Makefile
    ├── push_swap.c
    ├── push_swap.h
    ├── movements*.c
    ├── sorting*.c
    ├── utils*.c
    ├── errors.c
    └── libft/

License

No license file is currently included in this repository.

If you want this to be usable beyond an academic context, consider adding a LICENSE file (MIT/Apache-2.0 are common choices) and updating this section accordingly.