2_is_looping2.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   2_is_looping2.c                                    :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: kpeng <marvin@42.fr>                       +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2018/10/04 02:09:23 by kpeng             #+#    #+#             */
/*   Updated: 2018/10/04 02:09:26 by kpeng            ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

typedef struct s_node {
	int value;
	struct s_node *next;
} Node;

#define SIZE 1000000

char hash_table[SIZE] = {0};

int is_looping(Node *node)
{
	Node *temp = node;
	unsigned long key;
	while (temp)
	{
		key = ((unsigned long)&temp->next) % SIZE;
		if (hash_table[key] != 0)
			return (1);
		else
			hash_table[key] = 1;
		temp = temp->next;
	}
	return (0);
}