HDU 2134 Cuts the cake

http://acm.hdu.edu.cn/showproblem.php?pid=2134

Problem Description

Ice cream took a bronze medal in the Beijing match. Liu sir is very very happy. So he buys a cake for them. kiki is a child who likes eating, so the task of cuting cake was given to kiki. kiki is also a mischievous child. She wants to cut the cake in a different way. This is introduced in the figure below.

But there is a difficult problem.which is how to make each preson get equally many cake. kiki is not good at match, so she wants you help her solve this problem. 

 

Input

Input contains multiple test cases. Each line is a case.　Each case contains only one integer R which is the radius. The input is terminated with a R of 0.

 

Output

For each test case, you should printf two numbers r2 and r1 in a line, accurate up to 3 decimal places, separate them by one space.

 

Sample Input

10

15

5

25

0

 

Sample Output

5.774 8.165

8.660 12.247

2.887 4.082

14.434 20.412

 

代码：

#include <bits/stdc++.h>
using namespace std;

int main() {
    double R;
    while(cin >> R) {
        if(R == 0)
            break;

        double r1, r2;
        r1 = sqrt(R * R / 3.0);
        r2 = sqrt(R * R * 2.0 / 3.0);

        printf("%.3lf %.3lf\n", r1, r2);
    }
    return 0;
}