hdu1012 u Calculate e

没什么好讲的

u Calculate e
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 36073 Accepted Submission(s): 16277

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

#include <cmath>#include <cstdio>int main(){    printf("n e\n");    printf("- -----------\n");    printf("0 1\n");    double sum=1;    int product=1;    for(int i=1;i<=9;i++){        product*=i;        sum+=1/(double)product;        if(i>=3)            printf("%d %.9f\n",i,sum);        else if(i==2)            printf("%d %.1f\n",i,sum);        else if(i==1)             printf("%d %.0f\n",i,sum);    }    return 0;}