set_cost.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   set_cost_of.c                                      :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: ana-lda- <ana-lda-@student.42.fr>          +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/07/16 13:38:28 by ana-lda-          #+#    #+#             */
/*   Updated: 2024/07/20 19:31:26 by ana-lda-         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "push_swap.h"

/** @brief This function defines the index of each element of the stack
 * and marks if it is over the median.*/
void	index_median(t_stack **stack)
{
	int		i;
	t_stack	*temp;
	int		median;

	median = ft_stack_size(stack) / 2;
	i = 0;
	temp = *stack;
	while (temp)
	{
		temp->index = i;
		if (i < median)
			temp->above_median = true;
		else
			temp->above_median = false;
		i++;
		temp = temp->next;
	}
}

void	refine_cost(t_stack *temp, t_stack **stack_a, t_stack **stack_b)
{
	int	size_a;
	int	size_b;

	size_a = ft_stack_size(stack_a);
	size_b = ft_stack_size(stack_b);
	if (temp->above_median && temp->target->above_median)
	{
		if (temp->index < temp->target->index)
			temp->cost -= temp->index;
		else
			temp->cost -= temp->target->index;
	}
	else if (!(temp->above_median) && (!temp->target->above_median))
	{
		if (size_a - temp->index < size_b - temp->target->index)
			temp->cost -= size_a - temp->index;
		else
			temp->cost -= size_b - temp->target->index;
	}
}

/** @brief this funcion defines the cost of sending an
 *  element of a to b*/
void	cost_of_a(t_stack **stack_a, t_stack **stack_b)
{
	t_stack	*temp;

	temp = *stack_a;
	while (temp)
	{
		if (temp->above_median)
			temp->cost = temp->index;
		if (!(temp->above_median))
			temp->cost = ft_stack_size(stack_a) - temp->index;
		if (temp->target->above_median)
			temp->cost += temp->target->index;
		if (!(temp->target->above_median))
			temp->cost += ft_stack_size(stack_b) - temp->target->index;
		refine_cost(temp, stack_a, stack_b);
		temp = temp->next;
	}
}

void	cost_of_b(t_stack **stack_a, t_stack **stack_b)
{
	t_stack	*temp;

	temp = *stack_b;
	while (temp)
	{
		if (temp->above_median)
			temp->cost = temp->index;
		if (!temp->above_median)
			temp->cost = ft_stack_size(stack_b) - temp->index;
		if (temp->target->above_median)
			temp->cost += temp->target->index;
		if (!(temp->target->above_median))
			temp->cost += ft_stack_size(stack_a) - temp->target->index;
		refine_cost(temp, stack_b, stack_a);
		temp = temp->next;
	}
}