stack.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   stack.c                                            :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: abertran <abertran@student.42.fr>          +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2023/02/20 22:10:18 by abertran          #+#    #+#             */
/*   Updated: 2023/02/23 18:34:18 by abertran         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "push_swap.h"

/*	Creates a element(nodo) in the stack with the provided value.
	Returns the newly created stack element. */

t_stack	*stack_new(int value)
{
	t_stack	*new;

	new = malloc(sizeof(t_stack));
	if (!new)
		return (NULL);
	new->value = value;
	new->index = 0;
	new->pos = -1;
	new->target = -1;
	new->cost_a = -1;
	new->cost_b = -1;
	new->next = NULL;
	return (new);
}

/*	Adds an element to the bottom of a stack. */

void	stack_add(t_stack **stack, t_stack *new)
{
	t_stack	*bottom;

	if (!new)
		return ;
	if (!*stack)
	{
		*stack = new;
		return ;
	}
	bottom = get_bottom(*stack);
	bottom->next = new;
}

/*	Returns the last element of the stack. */

t_stack	*get_bottom(t_stack *stack)
{
	while (stack && stack->next != NULL)
		stack = stack->next;
	return (stack);
}

/* Returns de element before the bottom element */

t_stack	*before_bottom(t_stack *stack)
{
	while (stack && stack->next->next != NULL)
		stack = stack->next;
	return (stack);
}	

/*	Returns the number of elements in a stack. */

int	get_stack_size(t_stack	*stack)
{
	int	size;

	size = 0;
	if (!stack)
		return (0);
	while (stack)
	{
		stack = stack->next;
		size++;
	}
	return (size);
}