程序分析,给出运算结果.

程序分析,给出运算结果.#include \x05class Sample\x05{\x05int x;public:\x05Sample(int a){ x = a; }friend double square(Sample & s);\x05};double square(Sample & s){ return s.x*s.x; }\x05void main()\x05{\x05Sample s1(20);\x05Sample s2(30);\x05cout