fernandamatt/2stack_ordering

An algorithm to sort data using two stacks.

2stack_ordering

An algorithm to sort data using two stacks.

A program wiritten in C to sort data using two stacks and a limitted set of movements.

The program calculates and displays on the standard output the movements necessary to order the stack entered.

The avaiable moviments are:

• 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

Usage

The program takes in the n numbers of the stack to be ordered, from top (x0) to bottom (xn), separated by spaces.

./push_swap x0 x1 ... x(n-1) xn