HDU-1012-u Calculate e( C++ && 2000年纽约水果)

u Calculate e

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 39216    Accepted Submission(s): 17804

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

 

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题意很简单：

让你根据的它的输出格式.... 按照下面这个公式.

输出 当n为0~9 的答案. 农夫山泉的说......

#include<iostream>#include<iomanip>#include<cstdio>using namespace std;int factorial(int a){    int temp = 1;    for(int i=a;i>0;i--)    {        temp = temp*i;    }    return temp;}int main(){    cout<<"n e"<<endl;    cout<<"- -----------"<<endl;    for(int i=0;i<10;i++)    {        double sum = 0;        cout<<i<<" ";        for(int j=0;j<=i;j++)        {            sum +=(1.0)/factorial(j);        }        if(i>2)            cout<<setprecision(9)<<std::fixed<<sum<<endl;        //从第三位开始保留9位小数.        else            cout<<sum<<endl;    }    return 0;}