hdu 1012 u Calculate e

u Calculate e

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 44729    Accepted Submission(s): 20522

Problem Description

A simple mathematical formula for e is



where n is allowed to go to infinity. This can actually yield very accurate approximations of e using relatively small values of n.

 

Output

Output the approximations of e generated by the above formula for the values of n from 0 to 9. The beginning of your output should appear similar to that shown below.

 

Sample Output

n e
- -----------
0 1
1 2
2 2.5
3 2.666666667
4 2.708333333

 

Source

Greater New York 2000

#include<iostream>
#include<math.h>
#include<string>
#include<algorithm>
using namespace std;
int jc(int n)
{
	int k=1;
	for(int i=1;i<=n;i++)
	  	k=k*i;
	return k;
}
int main()
{ 
    cout<<"n e"<<endl;
    cout<<"- -----------"<<endl;
    cout<<"0 1"<<endl;
    double sum=1;
    for(int i=1;i<=9;i++)
    {   
        sum+=1.0/jc(i);
        if(i>2)
        	printf("%d %.9lf\n",i,sum);
        else
    	cout<<i<<" "<<sum<<endl;
	}
    
}