求N的阶乘的最后一位数字

#include <iostream>

  

usingnamespace std;

  

int main()

{

    inti,n,sum;

    while(cin>>n)

    {

        sum=1;

    for(i=1;i<=n;i++)

    {

        sum=sum*i;

  

        if(sum>10)

        {

            if(sum!=0)

            {

                sum=sum;

            }

            else

            {

                sum=sum/10;

            }

        }

    }

    cout << sum << endl;

    }

    return0;

}