（hdu）1042 N! 大数相乘

题目链接：http://acm.split.hdu.edu.cn/showproblem.php?pid=1042

Problem Description
Given an integer N( ≤ N ≤ ), your task is to calculate N!

Input
One N in one line, process to the end of file.

Output
For each N, output N! in one line.

Sample Input

Sample Output

题意：求N！（N<10000）

方法：用数组储存数，因为位数太多，每位存5个数

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>
using namespace std;
#define N 10010
#define met(a,b) memset(a,b,sizeof(a));
vector<vector<int> >Q;
int a[N],n;
void add(int m)
{
    for(int i=;i<N;i++)
    {
        a[i]=a[i]*m;
    }
    for(int i=;i<N-;i++)
    {
        a[i+]+=a[i]/;
        a[i]=a[i]%;
    }
}
void put(int a[])
{
    int i=N-;
    while(!a[i])i--;
    printf("%d",a[i]);
    for(i--;i>=;i--)
        printf("%04d",a[i]);
    puts("");
}
void init()
{
    a[]=;
    for(int i=;i<=n;i++)
    {
        add(i);
    }
}
int main()
{
    while(scanf("%d",&n)!=EOF)
    {
        if(n==)
        {
             printf("1\n");
             continue;
        }

        met(a,);
        init();
        put(a);
    }
    return ;
}