Push_swap

A 42 school project that sorts a stack of integers using a limited set of operations and two stacks, while minimizing the number of operations performed. A bonus checker program verifies that a given sequence of operations correctly sorts the stack.

Operations

push_swap and checker operate on two stacks (a and b) using the following instructions: sa, sb, ss (swap), pa, pb (push), ra, rb, rr (rotate), rra, rrb, rrr (reverse rotate).

Algorithm

Numbers are pushed to stack b, split into chunks, and repositioned based on the cheapest combination of rotate/reverse-rotate operations before being pushed back onto stack a in sorted order. The cost of each possible move is computed for every number to choose the most efficient path.

Build

make        # builds push_swap
make bonus  # builds the checker program
make clean  # removes object files
make fclean # also removes the executables
make re     # rebuilds everything

Usage

./push_swap 2 1 3 6 5 8

Prints the list of operations needed to sort the stack.

./checker 2 1 3 6 5 8

Reads operations from standard input and prints OK if the stack ends up sorted, KO otherwise.

Constraints

• Follows the 42 Norm
• Compiles without errors or warnings (-Wall -Wextra -Werror)
• Relies on libft and ft_printf as internal libraries