push_swap/stack_operations.c at main · SebastiaoJeronimo/push_swap · GitHub

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/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   stack_operations.c                                 :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: scosta-j <scosta-j@student.42.fr>          +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2023/08/19 14:28:09 by scosta-j          #+#    #+#             */
/*   Updated: 2023/08/22 18:08:25 by scosta-j         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "stack.h"

/**
 * @brief takes a element from stack1 (pop) and puts in the  stack2 (push)
 *
 * @param stack_1 stack which the element is going to be removed (pop)
 * @param stack_2 stack which the element is going to be pushed (push)
 * @returns 1 if sucessfull and 0 if not succesful
 * its not sucessful if the 1 stack is empty
 */
int	push(t_list **stack_1, t_list **stack_2)
{
	t_list	*head_1;

	if (!*stack_1)
		return (0);
	head_1 = *stack_1;
	*stack_1 = (*stack_1)->next;
	head_1->next = *stack_2;
	*stack_2 = head_1;
	return (1);
}

/**
 * @brief swaps the first two elements of the stack
 *
 * @param stack the stack that we are going to swap the first two elements
 * @return int 1 if sucessful 0 if stack empty or has one element
 */
int	swap(t_list	**stack)
{
	t_list	*first;
	t_list	*second;
	t_list	*third;

	if (!*stack || !(*stack)->next)
		return (0);
	first = *stack;
	second = (*stack)->next;
	third = second->next;
	first->next = third;
	second->next = first;
	*stack = second;
	return (1);
}

/**
 * @brief rotates the stack the first element becomes the last one
 *
 * @param stack stack in which the operation is going to be performed
 * @return int 1 if sucessfull 0 if empty or has one element
 */
int	rotate(t_list **stack)
{
	t_list	*first;
	t_list	*second;
	t_list	*last;

	if (!*stack || !(*stack)->next)
		return (0);
	first = *stack;
	second = first->next;
	last = *stack;
	while (last->next)
		last = last->next;
	first->next = NULL;
	last->next = first;
	*stack = second;
	return (1);
}

/**
 * @brief reverse rotate the last element of the stack becomes the first one
 *
 * @param stack the stack in which the operation is going to be performed
 * @return int 1 if is sucessfull 0 if its not
 */
int	rev_rotate(t_list **stack)
{
	t_list	*first;
	t_list	*last;
	t_list	*new_last;

	if (!*stack || !(*stack)->next)
		return (0);
	first = *stack;
	last = *stack;
	while (last->next)
	{
		new_last = last;
		last = last->next;
	}
	new_last->next = NULL;
	last->next = first;
	*stack = last;
	return (1);
}