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): 40905    Accepted Submission(s): 18610

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<stdio.h>
using namespace std;
int main()
{
    printf("n e\n- -----------\n");
    double ans=2.5;
    double tmp=2;
    printf("0 1\n");
    printf("1 2\n");
    printf("2 2.5\n");
    for(int i=3;i<10;i++)
    {
        tmp*=i;
        ans+=1/tmp;
        printf("%d %.9lf\n",i,ans);
    }
}

水题，注意精度就行。