Question

用c#写:有1,2,3,4个数字,能组成多少个互不相同且无重复数字的三位数?都是多少?

Answer 1

不讲究时间复杂度的话,程序如下

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace ConsoleApplication5

{

class Program

{

static void Main(string[] args)

{

int _sum = 0;

for (int _tmpi = 1; _tmpi < 5; _tmpi++)

{

for (int _tmpj = 1; _tmpj < 5; _tmpj++)

{

for (int _tmpk = 1; _tmpk < 5; _tmpk++)

{

if ((_tmpi == _tmpj) && (_tmpj == _tmpk) && (_tmpi == _tmpk))

{

continue;

}

else

{

int tem = _tmpi * 100 + _tmpj * 10 + _tmpk;

_sum++;

Console.WriteLine(tem.ToString());

}

}

}

}

Console.WriteLine(_sum.ToString());

Console.ReadLine();

}

}

}

共60个