C语言计算两个圆周长差：程序示例与解析

#include <stdio.h>

double mylen(double r);

int main() { double r1, r2, len; r1 = 3.3; r2 = 5.5; len = mylen(r1) - mylen(r2); printf('len = %f\n', len); return 0; }

double mylen(double r) { double length; length = 2 * 3.14159 * r; return length; }

运行结果为：len = -9.849560