C program to sort data on a stack, with a limited set of instructions, using the lowest possible number of actions.
At the beginning, the stack a contains a random amount of negative and/or positive numbers which cannot be duplicated. The stack b is empty. To sort the numbers in ascending order into stack a, following operations can be used:
sa (swap a): Swap the first 2 elements at the top of stack a.
sb (swap b): Swap the first 2 elements at the top of stack b.
ss: sa and sb at the same time.
pa (push a): Take the first element at the top of b and put it at the top of a.
pb (push b): Take the first element at the top of a and put it at the top of b.
ra (rotate a): Shift up all elements of stack a by 1. (The first element becomes the last one).
rb (rotate b): Shift up all elements of stack b by 1. (The first element becomes the last one).
rr : ra and rb at the same time.
rra (reverse rotate a): Shift down all elements of stack a by 1. (The last element becomes the first one).
rrb (reverse rotate b): Shift down all elements of stack b by 1. (The last element becomes the first one).
rrr: rra and rrb at the same time.
To run:
make
Example:
./push_swap 2 4 7 5 12 65 1 -3
To count the number of operations, run:
ARG="2 4 7 5 12 65 1 -3"; ./push_swap $ARG | wc -l