阶乘末尾的K位

解题思路:

注意事项:

参考代码:

#include <stdio.h>

long long a[100];

int main()

{

        int n,m,k=0,i;

        long long sum=1;

        scanf("%d%d",&n,&m);

        for(i=2;i<=n;i++)

        {

                sum=sum*i;

                while(sum%10==0)sum=sum/10;

        }

        for(i=0;i<m;i++)

        {

                if(sum==0)break;

                a[k++]=sum%10;

                sum=sum/10;

        }

        for(i=k-1;i>=0;i--)printf("%d",a[i]);

        return 0;

}