数老鼠

题目描述

请实现一个老鼠类，下面已给出代码模板，请根据main函数中对该类的操作，补充类实现部分完成代码。

该类有个公有静态变量num记录该类的所有对象数，主函数将会在不同语句之后输出对象数，只有正确地实现该类，保证num正确记录该类的对象数，才能输出正确的结果。

#include <iostream>
using namespace std;
  
class Mouse{
/* Your code here! */
};
  
void fn(Mouse m);
  
int main()
{
    Mouse::num = 0;
    Mouse a;
    cout << Mouse::num << endl;
    Mouse b(a);
    cout << Mouse::num << endl;
    for (int i = 0; i < 10; ++i)
    {
        Mouse x;
        cout << Mouse::num << endl;
    }
    fn(a);
    cout << Mouse::num << endl;
    return 0;
}
  
void fn(Mouse m)
{
    cout << Mouse::num << endl;
    Mouse n(m);
    cout << Mouse::num << endl;
} 

　　输入描述 
输出描述

主函数的输出已经写好

/* students please write your program here */
#include <iostream>
using namespace std;

class Mouse {
public:
	static int num;
	Mouse() {
		num++;
	}
	Mouse(const Mouse& n) {
		num++;
	}
	~Mouse() {
		num--;
	}
};

void fn(Mouse m);
int Mouse::num = 0;
int main()
{
	Mouse::num = 0;
	Mouse a;
	cout << Mouse::num << endl;
	Mouse b(a);
	cout << Mouse::num << endl;
	for (int i = 0; i < 10; ++i)
	{
		Mouse x;
		cout << Mouse::num << endl;
	}
	fn(a);
	cout << Mouse::num << endl;
	return 0;
}

void fn(Mouse m)
{
	cout << Mouse::num << endl;
	Mouse n(m);
	cout << Mouse::num << endl;
}