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 1 1 2 2 2.5 3 2.666666667 4 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;
}