【ACM】大数阶乘 – Java BigInteger实现详解编程语言

  
#include <iostream> 
#include <cmath> 
#include <algorithm> 
#include <cstdio> 
 
using namespace std; 
 
int main(){ 
 
    int n; 
    cin>>n; 
    if (n==1||n==0) 
    { 
        cout<<"1"<<endl; 
    }else{ 
 
        int a[100000] = {0}; 
        int i,j,k,sum,t; 
        a[0] = 1; 
        k = 1; 
        for (i = 2; i <= n ; i++) 
        { 
            sum = 0; 
            for (j = 0; j < k ; j++) 
            { 
                t = a[j]*i + sum; 
                a[j] = t % 10; 
                sum = t/10; 
            } 
            while(sum){ 
                a[k++] = sum%10; 
                sum /= 10; 
            } 
        } 
        for (int z = k-1; z>=0 ; z--) 
        { 
            cout<<a[z]; 
        } 
        cout<<endl; 
 
    } 
 
 
 
    return 0; 
}