杭电 1012 u Calculate e

u Calculate e

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 33475    Accepted Submission(s): 15104

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 11 22 2.53 2.6666666674 2.708333333

 

Source

Greater New York 2000

 

 

#include<iostream>using namespace std;int result(int x){int sum=1;for(int i=1;i!=x+1;i++){sum*=i;}return sum;}int main(){double  sum=2.5;cout<<'n'<<" "<<'e'<<endl<<"- -----------"<<endl;cout<<0<<" "<<1<<endl<<1<<" "<<2<<endl<<2<<" "<<2.5<<endl;for(int i=3;i<=9;i++){sum+=1.0/result(i);printf("%d %.9lf\n",i,sum);}return 0;}