#include <iostream>
using namespace std;
void Calculate(int x=1,int y=2,int z=3) {
int t=x+y+z; cout<< “The result is: ”<<t<<endl; }
int main(){ 程序 1 执行结果为：The result is:60
Calculate(10,20,30); The result is:33
Calculate(10,20); The result is:15
Calculate(10); The result is:6
Calculate();
return 0;
}
2、（8 分）
#include <iostream>
using namespace std;
class Point {
public:
Point(int xx = 0, int yy = 0) {x=xx; y=yy; out << "The constructor is called " << endl;}
Point(Point &p);
int getX() { return x; }
int getY() { return y; }
private:
int x, y;
};
Point::Point(Point &p) {
x = p.x; y = p.y;
cout << "The copy constructor is called " << endl;
}
void fun1(Point p) { cout << p.getX() << endl; }
Point fun2()
{ 程序 2 执行结果为：The constructor is called
Point a(1, 2); The copy constructor is called
return a; 7
} The copy constructor is called
int main() { 7
Point a(7, 8); The copy constructor is called
Point b = a; 1
cout << b.getX() << endl;
fun1(b);
b = fun2();
cout << b.getX() << endl;
return 0;
}
3、（6 分）
#include <iostream>
using namespace std;
class Base1 {
public:
Base1(int i) { cout << "Constructing Base1 " << i << endl; }
};
class Base2 {
public: Base2(int j) { cout << "Constructing Base2 " << j << endl; } };
class Base3 {
public:
Base3() { cout << "Constructing Base3 *" << endl; }
};
class Derived: public Base2, public Base1, public Base3 { public:
Derived(int a, int b, int c, int d): Base1(a), member2(d), member1(c), Base2(b) { } private:
Base1 member1;
Base2 member2;
Base3 member3;
};
int main() {
Derived obj(1, 2, 3, 4);
return 0;
}
程序 3 执行结果为：
Constructing Base2 2
Constructing Base1 1
Constructing Base3 *
Constructing Base1 3
Constructing Base2 4
Constructing Base3 *
1、（12 分）下面程序段通过抽象类 Shape 实现运行时多态。已知 Shape 类中有两个纯虚函数，名称分别为 getName()和 getArea()，shape 基类派生出直角三角形 Triangle 类和矩形 Rectangle 类，且程序运行结果为：
请填空完成程序。
#include<iostream>
using namespace std;
class Shape{
public:
virtual char* getName() = 0;
virtual double getArea() = 0;
};
class Triangle:public Shape{
double width, height;
public:
Triangle(double w,double h):width(w),height(h){}
char* getName(){
return "三角形";
}
double getArea(){
return (width*height) / 2;
}
};
class Rectangle:public Shape{
double width,length;
public:
Rectangle(double wid,double len):width(wid),length(len){} char* getName(){
return "矩形";
}
double getArea(){
return width*length;
}
};
int main(){
Shape* ps;
Triangle t(10,5);
Rectangle r(2,8);
ps=&t;
cout<<"形状:"<<ps->getName()<<",面积:"<<ps->getArea()<<endl;
ps=&r;
cout<<"形状:"<<ps->getName()<<",面积:"<<ps->getArea()<<endl;
return 0;
}