ft_isprime.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_isprime.c                                       :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: akharrou <akharrou@student.42.fr>          +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2019/02/21 17:57:45 by akharrou          #+#    #+#             */
/*   Updated: 2019/02/21 17:58:11 by akharrou         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

int		ft_isprime(int n)
{
	int i;

	if (n < 2)
		return (0);
	if (n == 2 || n == 3 || n == 5 || n == 7)
		return (1);
	if (n % 2 == 0 || n % 3 == 0 || n % 5 == 0 || n % 7 == 0)
		return (0);
	i = 7;
	while ((i * i) <= n)
	{
		if (n % i == 0)
			return (0);
		i += 2;
	}
	return (1);
}