Problem Description
A simple mathematical formula for e is
![](http://acm.hdu.edu.cn/data/images/1012-1.gif)
where n is allowed to go to infinity. This can actually yield very accurate approximations of e using
![](http://acm.hdu.edu.cn/data/images/1012-1.gif)
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<stdio.h> int main() { double e[10] = {1}; double sum = 1; double ans = 0; int i; for (i = 1; i < 10; i++) { sum *= (double)i; e[i] = 1 / sum; } printf("n e\n"); printf("- -----------\n"); for (i = 0; i < 10; i++) { ans += e[i]; if (i <= 2) printf("%d %g\n", i, ans); else printf("%d %.9f\n", i, ans); } return 0; }