华南师大上机真题(面向对象上机编程总结)

类与封装

引入静态变量，统计对象的个数

继承与封装

多态

华南师范大学上机真题

$四、酒店场景。$
$要求$：

定义一个客人类 Guest。包含成员属性：编号 Num、姓名 Name、房费 Fee、当前酒店入住人数 Count。
其中编号 Num 需要程序自动生成。
现在要求实现以下 Guest 的成员函数：构造函数、Show()显示 Guest 的信息、 GetCount()返回当前酒店入住的人数、GetTotalIncome()返回当前酒店的总收入。
并定义 3 个 Guest 对象来对成员函数进行测试。

样例:

#include<bits/stdc++.h>
using namespace std;
class Guest
{
	public:
		Guest(string Nick , int cost);	
		static int cnt;
		static int sum_cost;
		static int GetTotalIncome()
		{
			return sum_cost;
		}
		static int GetCount()
		{
			return cnt;
		}
		void show();
		string name;
		int fee;
		int num;
};
int Guest :: cnt = 0;
int Guest :: sum_cost = 0;
void Guest :: show()
{
	cout << "Name : " << name << endl;
	cout << "Num :" << num << endl;
	cout << "Fee :" << fee << endl;
}
Guest :: Guest(string Nick , int cost)
{
	cnt ++;
	name = Nick , fee = cost;
	num = cnt;
	sum_cost += cost;
}
int main()
{
	Guest aa("张三" , 900);
	Guest bb("李四" , 100);
	Guest cc("王五" , 1000);
	cout <<"Now Count :" << aa.GetCount() << endl;
	cout << "Now income :" << aa.GetTotalIncome() << endl;
	aa.show();
	bb.show();
	cc.show(); 
}

$五、抽象类Shape$
$要求：$它拥有一系列虚函数：Input()输入类需要的信息、Show() 显示类的信息、Perimeter()计算周长、Area()计算面积。
先定义 Circle、Square、 Triangle 来继承 Shape 并实现其虚函数。要求创建 Circle、Square、Triangle 的对象，用基类指针指向这些对象，并调用成员函数。
样例输入：

input radius:2  

input length of each side:3 4 5

input width and height: 4 6

样例输出：

Radius:2
Area=12.5808
Perimeter=12.5664

Lenght_A:3
Lenght_B:4
Lenght_C:5
Area=6
Perimeter=12

width:4
height:6
Area=24
Perimeter=20

#include<bits/stdc++.h>
using namespace std;
#define PII 3.1415926
class Shape
{
	public:
		virtual void Input() = 0;
		virtual void Show() = 0;
		virtual double Perimeter() = 0;
		virtual double Area() = 0;
};
//圆形 
class Circle : public Shape
{
	public:
		double radius;
		virtual double Perimeter();
		virtual double Area();
		virtual void Input()
		{
			double r;
			cin >> r;
			radius = r;
		}
		virtual void Show();

};
void Circle :: Show()
{
	cout << "Radius:" << radius << endl;
	cout << "Area=" << Area() << endl;
	cout <<"Perimeter=" << Perimeter() << endl;
}
double Circle :: Perimeter()
{
	double ans = 2 * PII * radius;
	return ans;
}
double Circle :: Area()
{
	double ans = PII * radius * radius;
	return ans;
}
//三角形 
class Triangle : public Shape
{
	public:
		double Lenght_A;
		double Lenght_B;
		double Lenght_C;
		virtual double Perimeter();
		virtual double Area();
		virtual void Input()
		{
			double a , b , c;
			cin >> a >> b >> c;
			Lenght_A = a , Lenght_B = b , Lenght_C = c;
		}
		virtual void Show()
		{
			cout << "Lenght_A:" << Lenght_A << endl;
			cout << "Lenght_B:" << Lenght_B << endl;
			cout << "Lenght_C:" << Lenght_C << endl;
			cout << "Area=" << Area() << endl;
			cout <<"Perimeter=" << Perimeter() << endl;
		}
};


double Triangle :: Perimeter()
{
	double ans = Lenght_A + Lenght_B + Lenght_C;
	return ans;
}
double Triangle :: Area()
{
	double s = (Lenght_A + Lenght_B + Lenght_C) / 2;
	double ans = sqrt(s * (s - Lenght_A) * (s - Lenght_B) * (s - Lenght_C));
	return ans;
}

//正方形 
class Square : public Shape
{
	public:
		double width;
		double heigh;
		virtual double Perimeter();
		virtual double Area();
		virtual void Input()
		{
			double w , d;
			cin >> w >> d; 
			width = w , heigh = d;
		}
		virtual void Show()
		{
			cout  << "width:" << width << endl;
			cout  << "heigh:" << heigh << endl;
			cout <<"Area=" << Area() << endl;
			cout <<"Perimeter=" << Perimeter() << endl;
		}
};
double Square :: Perimeter()
{
	double ans = 2 * (width + heigh);
	return ans;;
}
double Square :: Area()
{
	double ans = width * heigh;
	return ans;;
}

int main()
{
	cout << "input radius:";
	Shape *p; 
	Circle C;
	Square S;
	Triangle T;
	p = &C;
	p->Input(); // 1 . 要保证虚函数在每一个子类里传入的参数个数一致 
	p->Show(); //  2 . 写的每一个虚函数都要有对应的实现，不然无法创建子类 
	cout << "input length of each side:";
	p = &T;
	p->Input();
	p->Show();
	cout << "input width and height:";
	p = &S;
	p->Input();
	p->Show();
}