list_utils.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   list_utils.c                                       :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: bpochlau <poechlauerbe@gmail.com>          +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2023/11/10 09:06:16 by bpochlau          #+#    #+#             */
/*   Updated: 2023/11/18 20:02:43 by bpochlau         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "push_swap.h"

t_list	*ft_lstnew(int num)
{
	t_list	*new;

	new = malloc(sizeof(t_list));
	if (!new)
		return (NULL);
	new->num = num;
	new->i = 0;
	new->next = NULL;
	return (new);
}

void	ft_lstadd_front(t_list **lst, t_list *new)
{
	new->next = *lst;
	*lst = new;
}

t_list	*ft_lstlast(t_list *lst)
{
	if (!lst)
		return (NULL);
	while (lst->next)
		lst = lst->next;
	return (lst);
}

t_list	*ft_lstsecondlast(t_list *lst)
{
	if (!lst)
		return (NULL);
	if (!lst->next)
		return (NULL);
	while (lst->next->next)
		lst = lst->next;
	return (lst);
}

void	ft_lstadd_back(t_list **lst, t_list *new)
{
	t_list	*ptr;

	if (lst && *lst)
	{
		ptr = ft_lstlast(*lst);
		ptr->next = new;
	}
	else
		*lst = new;
}