Hdu1042 N! （阶乘高精度模板）

Problem Description

Given an integer N(0 ≤ N ≤ 10000), 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

1

2

3

 

Sample Output

1

2

6

 

模板，每次计算阶乘数值，并将每位数值存放在数组中，模拟手算的原理，每次从低位开始乘，逐步到高位，期间不停更新数组中的数值。

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <string.h>
using namespace std;
const int maxn=40000;
int d[maxn];
int main()
{
    int n;
    while(cin>>n){
        memset(d,0,sizeof(d));
        d[0]=1;
        int t=0,tmp=0,carry=0;
        for(int i=1;i<=n;i++){
            for(int j=0;j<=t;j++){
                tmp=d[j]*i+carry;
                d[j]=tmp%10;
                carry=tmp/10;
            }
            while(carry!=0){
                d[++t]=carry%10;
                carry/=10;
            }
        }
        for(int i=t;i>=0;i--){
            cout<<d[i];
        }
        cout<<endl;
    }
    return 0;
}