椭圆的半周长和面积的计算的方式，运用C语言的编程的技术的实现

Question

Problem Description

There is a wall in your backyard. It is so long that you can’t see its endpoints. You want to build a fence of length L such that the area enclosed between the wall and the fence is maximized. The fence can be of arbitrary shape, but only its two endpoints may touch the wall.

Input
The input consists of several test cases.
For every test case, there is only one integer L (1<=L<=100), indicating the length of the fence.
The input ends with L=0.

Output
For each test case, output one line containing the largest area. Your answer should be rounded to 2 digits after the decimal point.

Sample Input
1
100
0

Sample Output
0.16
1591.55

Answer 1

#include
#include
#define PAI 3.14159265
void main()
{
float a,b;
float S,L;
printf("输入长半轴a，短半轴b:");
scanf("%f%f,&a,&b");
S = PAI*a*b;
L = 2*PAI*b+4*(a-b);
printf("面积=%f,周长=%f",S,L);
}