The Push swap project is a very simple and a highly straightforward algorithm project: data must be sorted. You have at your disposal a set of integer values, 2 stacks, and a set of instructions to manipulate both stacks. Your goal? Write a program in C called push_swap which calculates and displays on the standard output the smallest program, made of Push swap language instructions, that sorts the integers received as arguments.
- You have 2 stacks named a and b.
- 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.
- The goal is to sort in ascending order numbers into stack a. To do so you have the following operations at your disposal:
sa (swap a): Swap the first 2 elements at the top of stack a.
Do nothing if there is only one or no elements.
sb (swap b): Swap the first 2 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 a): Take the first element at the top of b and put it at the top of a.
Do nothing if b is empty.
pb (push b): Take the first element at the top of a and put it at the top of b.
Do nothing if a is empty.
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 illustrate the effect of some of these instructions, let’s sort a random list of integers. In this example, we’ll consider that both stacks grow from the right.
