using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp1
{
class Class2
{
    static void Main(string[] args)
    {
        Console.WriteLine("整数1不是素数!");
        for (int m = 2; m<= 100; m++) {
            bool flag = true;
            int k = (int)(Math.Sqrt(m));
            int i = 2;
            while (i <= k && flag == true)
            {
                if (m % i == 0) flag = false;
                else i++;
            }
            if (flag == true)
                Console.WriteLine("整数{0}是素数!", m);
            else
                Console.WriteLine("整数{0}不是素数!", m);
        }
        Console.ReadKey();
    }

}

效果图: