Push_swap

This project for sorting numbers using Quick sort algorithm (Wikipedia link) for 2 stacks with my own improvements

This project is about sorting numbers considering two stacks and using only the following instructions:

• 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 flast element becomes the first one.
• rrb : reverse rotate b - shift down all elements of stack b by 1. The flast element becomes the first one.
• rrr : rra and rrb at the same time

Algorithm speed

In theory:

In worth cases θ(n x log(n)) - θ(n^2) - for simple quick sort

In reality:

• For 100 numbers max - 700 instructions
• For 500 numbers max - 5300 instructions

Compile

> make all

Usage

push_swap program for generate instruction set, checker program for check and test instruction set

To generate the set of instructions for a set of numbers:

> ./push_swap n1 n2 n3 n4 n5 n6 ...

and to check wether the set of instructions really sorts:

> ./push_swap n1 n2 n3... | ./checker n1 n2 n3 ...