51NOD 1057 N的阶乘

#include <bits/stdc++.h>
#define clear(a) memset(a,0,sizeof(a))
using namespace std;
typedef long long ll;
const int mod = 1e8;
ll s[10010];

int main ()
{
    int n;
    while (~scanf("%d",&n) )
    {
        clear(s);
        int m =0;
        s[0] = 1;
        for(int i=1;i <= n;i++)
        {
            int c = 0;//c表示最高位所留下的  相当于模拟乘法把
            for(int j=0;j <= m;j++)
            {
                s[j] = s[j]*i + c;
                c = s[j] /mod;
                s[j] %= mod;
            }
            if(c > 0)
            {
                m++;
                s[m] = c;
            }
        }
        printf("%lld",s[m]);
        for(int i=m-1;i >= 0;i--)
            printf("%08lld",s[i]);
        puts("");
    }
    return 0;
}