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c++实验多态程序设计

2026/8/29 9:35:22 拓冰建站 浏览量
c++实验多态程序设计
  1. 运行程序，分析结果。

#include <iostream>

using namespace std;

class B

{

public:

    virtual void f1(double x)

    {

        cout<<"B::f1(double)"<<x<<endl;

    }

    void f2(double x)

    {

        cout<<"B::f2(double)"<<2*x<<endl;

    }

    void f3(double x)

    {

        cout<<"B::f3(double)"<<3*x<<endl;

    }

};

class D:public B

{

public:

    virtual void f1(double x)

    {

        cout<<"D::f1(double)"<<x<<endl;

    }

    void f2(double x)

    {

        cout<<"D::f2(double)"<<2*x<<endl;

    }

    void f3(double x)

    {

        cout<<"D::f3(double)"<<3*x<<endl;

    }

};

int main()

{   D d;

    B* pb=&d;

    D* pd=&d;

    pb->f1(1.23);

    pd->f1(1.23);

    pb->f2(2.23);

    pd->f2(2.23);

    pb->f3(3.23);

    pd->f3(3.23);

    return 0;

}

运行结果pb与pd一样，基类f1为虚函数，派生类D为虚函数并重写了f1
因此调用派生类版本
运行结果与传入实参相关，若修改pd结果运行结果就改变
改变类D的函数体结果与形参和函数体定义相关,类D函数f1（）为虚函数对象pb为类D的实例所以改变类D的函数体后对象pb的f1()的运行结果，虚函数是根据对象的不同调用不同类的虚函数，pb是动态联编，pb的f1结果为pb的f1结果

 

运行下面的程序，分析运行结果；再把基类的析构函数定义为virtual，再运行程序，分析运行结果，体会将基类的析构函数定义为虚析构函数的作用。

#include <iostream>

using namespace std;

class BaseClass

{

public:

    BaseClass(){cout<<"BaseClass()"<<endl;}

     ~BaseClass() { cout<<"~BaseClass()"<<endl;}

};

class DerivedClass:public BaseClass

{

public:

    DerivedClass(){cout<<"DerivedClass()"<<endl;}

    ~DerivedClass(){ cout<<"~DerivedClass()"<<endl;}

};

int main()

{

    BaseClass *bp=new DerivedClass();

    delete bp;

    return 0;

}

 最先调用基类的构造函数，其次调用派生类的构造函数，调用基类的构造函数，最后只是调用了基类的构造函数基类的析构函数声明为虚构函数以后调用派生类的构造函数，调用基类的构造函数，调用派生类的构造函数，调用基类的构造函数

编写程序，计算三角形、正方形和圆形这3种图形的周长和面积，并在main函数中使用相关数据进行测试。要求：

（1）抽象出一个基类Shape类，从其派生出Triangle类（三角形类）、Square（正方形类）、Circle（圆形类）。

Shape类中定义3个protected数据成员供派生类使用，派生类中无需定义数据成员。

Shape类中定义求面积getArea()和求周长getcircumference()成员函数为虚函数。其派生类中分别重定义各自的求面积和求周长函数。

#include<iostream>
using namespace std;
#define PI 3.14
class Shape
{
public:Shape(){}~Shape() {};virtual double getArea() const{return 0.0;}virtual double getcircumference()const{return 0.0;}protected:double x;double y;double z;private:};class Triangle:public Shape  
{
public:Triangle(){}Triangle(double X, double Y, double Z) {x = X;y = Y;z = Z;};~Triangle() {};virtual double  getcircumference() const{return (x + y + z);}virtual double getArea() const{double a= (x + y + z)/2;//海伦公式double s= (a*(a-x)*(a-y)*(a-z));return s;}private:};class Square: public Shape
{
public:Square() {};Square(double X) {x = X;};~Square() {};virtual double getArea() const{return x * x;}virtual double getcircumference()const{return 4 * x;}private:};class Circle :public Shape
{
public:Circle() {};~Circle() {};Circle(double X) {x = X;};virtual double getArea() const{return PI * x * x;}virtual double getcircumference()const{return PI * 2 * x;}private:};
void fun(Shape &s)
{cout << s.getcircumference()<<" ";cout << s.getArea()<<endl;}
int main()
{Triangle t(4,2,1);cout << "Triangle的周长和面积分别为：";fun(t);Square s(5);cout << "Square的周长和面积分别为：";fun(s);Circle c(3);cout << "Square的周长和面积分别为：";fun(c);}

  1. 一个游戏中有多种怪物(Monster)，怪物之间可能要发生战斗(fight)，每场战斗都是一个怪物与另一怪物之间的一对一战斗。每个怪物都有自己的生命值(hitpoint)、攻击力值(damage)和防御力值(defense)，每种怪物都有各自特有的攻击(attack)方式，产生相应的攻击效果；战斗时，两个怪物依次攻击对方，即怪物a首先攻击怪物b, 然后轮到怪物b攻击怪物a, 之后，怪物a再次攻击怪物b，…, 直到一方生命值为0。请根据你对上述描述的理解：（1）定义并实现怪物类Monster，成员的设计可以包括数据成员hitpoint、damage和defense，以及其他任意需要的成员函数。要求包括一个纯虚函数attack，作为派生类对象各自实现攻击细节的接口；要求定义一个非虚的成员函数fight，用来描述与另外一个怪物进行战斗的过程，该函数的实现可为Monster类的任意派生类所复用（派生类不需重新定义及实现）。不必考虑怪物的生命值减少至0后如何处理。

  2. 猫进攻导致对方的生命值减少量：

    狗进攻导致对方的生命值减少量：

    （猫的攻击力值 * 2 — 对方的防御力值）

     若上式小于1，则取1

    (狗的攻击力值 — 对方的防御力值 ＋5 )*2

    若上式小于2，则取2

  3. 作为怪物的特例，猫和狗的攻击效果如下表所示。在Monster的基础上，以继承手段定义并实现这两个类。

  4. （3）再增加其他派生类，如Cock类，自行定义进攻对方的生命值减少量。

     自行设计并实现游戏的测试函数，输出相互攻击的实时生命力值，并给出胜负结果

    #include <iostream>
using namespace std;
class Monster
{
public:Monster(){}Monster(int hp, int dmg, int def) : hitpoint(hp), damage(dmg), defense(def) {}~Monster(){}virtual void attack(Monster& m) const = 0;void fight(Monster& m){cout << "战斗开始！" << endl;while (m.hitpoint>0&&hitpoint>0){attack(m);if (m.hitpoint > 0){m.attack(*this);}}cout << "战斗结束" << endl;}int hitpoint;  //血量int damage;   //攻击int defense;  //防御};
class Monster1:public Monster
{
public:Monster1(){}Monster1(int hp, int dmg, int def) : Monster(hp, dmg, def) {}~Monster1(){}void attack(Monster& m)const {cout << "Monster1 使用了恶龙咆哮！"<<endl;int dam = damage - m.defense;m.hitpoint -= dam;if (m.hitpoint <= 0) {cout << "Monster1赢了" << endl;m.hitpoint = 0;}cout << "造成了：" << dam << "点血量"<<endl;cout << "对方剩余" << m.hitpoint<<"点血量" <<endl;}private:};
class Monster2:public Monster
{
public:Monster2(){}Monster2(int hp, int dmg, int def) : Monster(hp, dmg, def) {}~Monster2(){}void attack(Monster& m) {cout << "Monster2 使用了群魔乱舞！" << endl;int dam = damage - m.defense;m.hitpoint -= dam;if (m.hitpoint <= 0){cout << "Monster2赢了" << endl;m.hitpoint = 0;}cout << "造成了：" << dam << "点血量" << endl;cout << "对方 剩余" << m.hitpoint << "点血量" << endl;}private:};
class CAT :public Monster
{
public:CAT(){}CAT(int hp, int dmg, int def) : Monster(hp, dmg, def) {}~CAT(){}void attack(Monster& m)const {cout << "CAT 使用了猫血旺！" << endl;int dam = (damage*2) - m.defense;cout << dam << endl;if (dam < 1)dam = 1;m.hitpoint -= dam;if (m.hitpoint <= 0){cout << "CAT" << endl;m.hitpoint = 0;}cout << "造成了：" << dam << "点血量" << endl;cout << "对方 剩余" << m.hitpoint << "点血量" << endl;}private:};
class DOG :public Monster
{
public:DOG(){}DOG(int hp, int dmg, int def) : Monster(hp, dmg, def) {}~DOG(){}void attack(Monster& m)const {cout << "DOG 使用了狗急了跳墙！" << endl;int dam =( damage  - m.defense+5)*2;if (dam < 2)dam = 2;m.hitpoint -= dam;if (m.hitpoint <= 0){m.hitpoint = 0;cout << "造成了：" << dam << "点血量" << endl;cout << "对方 剩余" << m.hitpoint << "点血量" << endl;cout << "DOG赢了" << endl;return;}cout << "造成了：" << dam << "点血量" << endl;cout << "对方 剩余" << m.hitpoint << "点血量" << endl;}private:};
class Cock:public Monster
{
public:Cock(){}Cock(int hp, int dmg, int def) : Monster(hp, dmg, def) {}~Cock(){}void attack(Monster& m)const {cout << "Cock 使用了公鸡独立！" << endl;int dam = (damage - m.defense + 50) ;if (dam < 2)dam = 2;m.hitpoint -= dam;if (m.hitpoint <= 0){m.hitpoint = 0;cout << "造成了：" << dam << "点血量" << endl;cout << "对方 剩余" << m.hitpoint << "点血量" << endl;cout << "Cock赢了" << endl;return;}cout << "造成了：" << dam << "点血量" << endl;cout << "对方剩余" << m.hitpoint << "点血量" << endl;}private:};
int main()
{//Monster1 m1(100, 30, 10);//Monster1 m2(100, 25, 8);//m1.fight(m2);CAT  c(50, 30, 10);//DOG d(90, 50, 40);Cock k(50, 50, 50);c.fight(k);}

    设计一个复数Complex类，实现复数的加、减运算，并实现复数的输入、输出。已知测试main函数如下：

    int main( )

    {

        Complex c1(5.0,10.0);    //5+10i

        Complex c2(3.0,-2.5);     //3-2.5i

        Complex c3,c4,c5=20;

        c3=c1+c2;

        c4=c1-5;

        cout<<c1<<c2<<c3<<c4;

        Complex c5;

        cout<<"请输入一个复数,实部和虚部以空格分开:"<<endl;

        cin>>c5;

        cout<<"输入的复数为:"<<c5<<endl;

        c4=5+c5;

        cout<<c4<<endl;

        return 0;

    }

    #include <iostream>
using namespace std;
class Complex {
private:double real;  // 实部double imag;  // 虚部public:// 构造函数Complex(double r = 0.0, double i = 0.0) : real(r), imag(i) {}// 加法运算Complex operator+(const Complex& other) const {return Complex(real + other.real, imag + other.imag);}// 实数 + 复数friend Complex operator+(double realPart, const Complex& c) {return Complex(realPart + c.real, c.imag);}// 实数 - 复数friend Complex operator-(double realPart, const Complex& c) {return Complex(realPart - c.real, -c.imag);}// 减法运算Complex operator-(const Complex& other) const {return Complex(real - other.real, imag - other.imag);}// 输出复数friend std::ostream& operator<<(std::ostream&os, Complex& c){os << c.real;if (c.imag >= 0)os << '+';os << c.imag <<"i" << endl;return os;}// 输入复数friend std::istream& operator>>(std::istream& is, Complex& c) {std::cout << "输入实部: ";is >> c.real;std::cout << "输入虚部: ";is >> c.imag;return is;}
};int main()
{Complex c1(5.0, 10.0);   	//5+10iComplex c2(3.0, -2.5);    	//3-2.5iComplex c3, c4, c5 = 20;c3 = c1 + c2;c4 = c1 - 5;cout << c1 << c2 << c3 << c4;Complex c6;cout << "请输入一个复数,实部和虚部以空格分开:" << endl;cin >> c6;cout << "输入的复数为:" << c5 << endl;c4 = 5 + c5;cout << c4 << endl;return 0;
}

    设计一个三角形类Triangle,包含三角形三条边长的私有数据成员，另有一个重载运算符“+",以实现求两个三角形对象的面积之和，进一步实现3个或更多的三角形对象相加的面积之和。

    分析提示：在Triangle类中设计一个友元函数double operator+(Triangle t1,Triangle t2),它重载运算符“+",返回t1和t2两个三角形的面积之和。

    已知测试main函数如下：

    int main()

     {

         Triangle tri1(3,4,5),tri2(6,8,10);

         double area1=tri1+tri2;

         cout<<area1<<endl;

         Triangle tri3(9,12,15);

         double area2=tri1+tri2+tri3;

         cout<<area2<<endl;

         return 0;

     }

    #include <iostream>
using namespace std;class Triangle
{
public:Triangle(double a=0, double b=0,double c=0){x = a;y = b;z = c;}~Triangle(){}friend double operator + (const Triangle& other1,const Triangle& other2){double a1 = (other1.x + other1.y + other1.z) / 2;double a2 = (other2.x + other2.y + other2.z) / 2;double s1 = sqrt(a1 * (a1 - other1.y) * (a1 - other1.x) * (a1 - other1.z));double s2 = sqrt(a2 * (a2 - other2.x) * (a2 - other2.y) * (a2 - other2.z));return s1 + s2;}friend double operator + (double snum,const Triangle& other){double a = (other.x + other.y + other.z) / 2;double s = sqrt(a * (a - other.y) * (a - other.x) * (a - other.z));cout << s << endl;return snum+s;}private:double x;double y;double z;
};
int main()
{Triangle tri1(3, 4, 5), tri2(6, 8, 10);double area1 = tri1 + tri2;cout << area1 << endl;Triangle tri3(9, 12, 15);double area2 = tri1 + tri2 + tri3;cout << area2 << endl;return 0;
}