题目：将一个正整数分解质因数。例如：输入90,打印出90=2*3*3*5。

c# codes as below:

using System;

namespace MyNamespace

{

class Program

{

static void Main(string[] args)

{

for (int i = 1; i <= 100; i++)

{

Fun(i);

}

Console.ReadKey();

}

public static void Fun(int number)

{

Console.Write("{0} = ",number);

int topNumber =(int) Math.Floor(Math.Sqrt(number));

int i = 2;

while (topNumber >= i)

{

if (number % i == 0)

{

Console.Write(" {0} *", i);

number = number / i;

topNumber = (int)Math.Floor(Math.Sqrt(number));

i = 2;

}

else

i++;

}

if (topNumber < i)

Console.WriteLine(" {0}", number);

}

}

}