歌德巴赫猜想

using System;
using System.Collections.Generic;
using System.Text;
/*
歌德巴赫猜想:任何一个大于6的偶数都可以写为两个素数之和
*/
namespace ExGoldbachConjecture
{
    class GoldbachConjecture
    {
        public bool IsPrimeNumber(int n)
        {
            bool b = true;
            if (n == 1 || n == 2)
                b = true;
            else
            {
                int sqr = Convert.ToInt32(Math.Sqrt(n));
                for (int i = sqr; i >= 2; i--)
                {
                    if (n % i == 0)
                    {
                        b = false;
                    }
                }
            }
            return b;
        }
        public bool goldbachConjecture(int n)
        {
            bool b = false;
            if (n % 2 == 0 && n > 6)
            {
                for (int i = 1; i <= n / 2; i++)
                {
                    bool b1 = IsPrimeNumber(i);//判断i是否为素数
                    bool b2 = IsPrimeNumber(n - i);//判断n-i是否为素数
                    if (b1 & b2)
                    {
                        Console.WriteLine("{0}={1}+{2}",n,i,n-i);
                        b = true;
                    }
                }
            }
            return b;
        }

        static void Main(string[] args)
        {
            Console.WriteLine("输入一个大于6的偶数");
            int n = Convert.ToInt32(Console .ReadLine ());
            GoldbachConjecture g=new GoldbachConjecture ();
            bool b = g.goldbachConjecture(n);
            if (b)
            {
                Console.WriteLine("{0}能写成两个素数的和。", n);
            }
            else
            {
                Console.WriteLine("猜想错误。你输入错误吧");
            }Console.ReadLine();
        }
    }
}