Push_swap

Description

Push_swap is a program that sorts a stack of integers using a specific set of operations. It takes a list of integers as an argument and displays the smallest list of instructions required to sort the stack in ascending order.

Usage

./push_swap <list of integers>

The stack is formatted as a list of integers, where the first argument is at the top of the stack.
Instructions are separated by a newline character ('\n').
If no parameters are specified, the program will not display anything and return to the prompt.

Instructions

The program uses the following set of operations to manipulate the stacks:

sa: Swap the first two elements at the top of stack A. (Do nothing if there is only one or no elements)
sb: Swap the first two elements at the top of stack B. (Do nothing if there is only one or no elements)
ss: sa and sb at the same time.
pa: Push the first element at the top of stack B to stack A. (Do nothing if stack B is empty)
pb: Push the first element at the top of stack A to stack B. (Do nothing if stack A is empty)
ra: Rotate all elements of stack A up by one. The first element becomes the last one.
rb: Rotate all elements of stack B up by one. The first element becomes the last one.
rr: ra and rb at the same time.
rra: Reverse rotate all elements of stack A down by one. The last element becomes the first one.
rrb: Reverse rotate all elements of stack B down by one. The last element becomes the first one.
rrr: rra and rrb at the same time.

Error Handling

If there are any errors, such as non-integer arguments, arguments exceeding the integer limit, or duplicate numbers, the program will display an error message: "Error\n".

Example

$> ./push_swap 2 1 3 6 5 8
sa
pb
pb
pb
sa
pa
pa
pa

Testing

During the evaluation process, a binary named checker_OS will be provided to check the correctness of the program's output. It works as follows:

$> ARG="4 67 3 87 23"; ./push_swap $ARG | wc -l
6
$> ARG="4 67 3 87 23"; ./push_swap $ARG | ./checker_OS $ARG
OK

If the checker_OS program displays "KO," it means that the list of instructions generated by push_swap does not sort the numbers correctly.