📖 Push_swap | 19 Brussels

💡 About the project

The Push swap project is a very simple and a highly straightforward algorithm project:

data must be sorted.

🎯 The goal is to sort the stack in an ascending order with the lowest possible number of operations.

---

💻 To use the program

you must first compile it with the makefile by using the command 'make' in the shell

make all

Then the program must be executed as follows:

./push_swap nb1 nb2 nb3 nbn...

---

❌ Error handling | Parsing

These lines should produce an Error :

• arguments aren’t integers.
• some arguments are bigger/smaller than an integer.
• there are duplicates.

---

❔ How it works ?

We have 2 stacks named a and b.

At the beginning stack b is empty and stack a contains the number given as arguments

Here are the operations we can execute :

Operations	Description
sa	swap first two elements of stack A
sb	swap first two elements of stack B
ss	sa and sb at the same time
pa	pops the first elememt on B and puts it on top of A
pb	pops the first elememt on A and puts it on top of B
ra	rotates stuck A up by one
rb	rotates stuck B up by one
rr	rotates both A and B up by one
rra	rotates stuck A down by one
rrb	rotates stuck B down by one
rrr	rotates both A and B down by one

I decided to implement the stack as a double-linked list and I use radix sorting, which works with the binary of the digits.
First I set a rank for each number I have to sort, making the smallest number rank 0, which makes me work only with positive values.
Then I compare each bit and decide whether to move it to stack b or not, repeating this operation until the stack A is sorted.