push_swap

A sorting algorithm implementation using two stacks and a limited set of operations, written in C.

About

Given a list of unsorted integers, push_swap outputs the sequence of operations needed to sort the integers in ascending order on stack A, using stack B as auxiliary space.

Available Operations

Operation	Description
sa	Swap the top two elements of stack A
sb	Swap the top two elements of stack B
pa	Push the top element of stack B onto stack A
pb	Push the top element of stack A onto stack B
ra	Rotate stack A upward (top element becomes last)
rb	Rotate stack B upward (top element becomes last)
rr	Rotate both stacks upward
rra	Reverse rotate stack A (last element becomes first)
rrb	Reverse rotate stack B (last element becomes first)
rrr	Reverse rotate both stacks

Algorithm

• 2–5 elements: Optimized hardcoded sorting routines.
• 6+ elements: A chunk-based approach that divides the sorted range into sqrt(n) chunks, pushes elements to stack B by range, then refills stack A by popping the maximum from B.

Build

make        # Build the push_swap executable
make clean  # Remove object files
make fclean # Remove object files and executable
make re     # Full rebuild

Usage

./push_swap 3 2 1
./push_swap "5 4 3 2 1"

The program prints the list of operations to stdout, one per line.

Project Structure

├── Makefile
├── lib/
│   └── push_swap.h
└── src/
    ├── main.c
    ├── sorting/
    │   ├── main_algo.c
    │   ├── check_len_tosort.c
    │   └── algo_utils.c
    ├── moves/
    │   ├── p_stacks.c
    │   ├── s_stacks.c
    │   ├── r_stacks.c
    │   └── rrr_stacks.c
    └── utils/
        ├── linked_lists.c
        ├── arg_pars.c
        ├── fillers_sortedarr.c
        ├── helper_functions.c
        ├── helper_functions_2.c
        └── helper_functions_3.c