编写一个算法，求数字是否为质数（素数）

Question

要求：输入一个数，算出该数是不是一个质数！？
谢谢帮助

Answer 1

自己研究 出来了，哈哈，给大家分享一下static void Main(string[] args)
        {
             int num;
            int i = 2;
            num = Convert.ToInt32(Console.ReadLine());            if (num % i == 0)
                i++;
            if (i == num)
            {
                Console.WriteLine("shi ");
            }
            else 
            {
                Console.WriteLine("bu ");
            }
               
            Console.ReadLine();
        }

Answer 2

你写错了，给你个正确的！！
using System;
using System.Collections.Generic;
using System.Text;namespace CheckPrime
{
    class Prime
    {
        public static bool isPrime(int num)
        {
            bool prime = true;
            for (int i = 2; i <= num / 2; i++)
            {
                if (num % i == 0)
                {
                    prime = false;
                    break;
                }
            }
            return (prime);
        }        static void Main(string[] args)
        {
            int num;
            char ch = 'y';            while (ch == 'y')
            {
                Console.Write("\nEnter a number :");
                num = Convert.ToInt32(Console.ReadLine());                if (isPrime(num))
                    Console.WriteLine("\nEntered number is a prime number.");
                else
                    Console.WriteLine("\nEntered number is not a prime number.");
                Console.Write("\nContinue? (y/n): ");
                ch = Convert.ToChar(Console.ReadLine());
            }
        }
    }
}