杭电 HDU 1042 N!

N!

Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 61718    Accepted Submission(s): 17632

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

 

Author

JGShining（极光炫影）

 一开始 不会做 但最后 终于能理解大数阶乘的算法了！

#include<iostream>
using namespace std;
int main()
{
	int ls[10001];
	int N,i,j;
	while(cin>>N)
	{
		int m=0;ls[0]=1;
		for( i=1;i<=N;i++)
		{
			int temp=0;
			for(j=0;j<=m;j++)
			{
				ls[j]=ls[j]*i+temp;
				temp=ls[j]/10000;
				ls[j]=ls[j]%10000;
			}
			if(temp)
			{
			    ls[++m]=temp;
			}
			
		}
		cout<<ls[m];
			for(int k=m-1;k>=0;k--)
				printf("%04d",ls[k]);
			cout<<endl;
	}
	return 0;
}