4-1 复数类的运算符重载
#include <iostream>
#include <algorithm>
using namespace std;class Complex
{
private:double real;double imag;
public:Complex(){real = 0;imag = 0;}Complex(double r, double i){real = r;imag = i;}Complex complex_add(Complex &c2);Complex complex_cut(Complex &c3);void display1();void display2();
};Complex Complex::complex_add(Complex &c2)
{Complex c;c.real = real+c2.real;c.imag = imag+c2.imag;return c;
}Complex Complex::complex_cut(Complex &c3)
{Complex d;d.real = real-c3.real;d.imag = imag-c3.imag;return d;
}void Complex::display1()
{cout<<real<<"+"<<imag<<"i"<<endl;
}void Complex::display2()
{cout<<real<<imag<<"i"<<endl;
}int main()
{Complex c1(3.2, 4.5),c2(8.9, 5.6), c3, c4;c3 = c1.complex_add(c2);c4 = c1.complex_cut(c2);cout<<"a=";c1.display1();cout<<"b=";c2.display1();cout<<"a+b=";c3.display1();cout<<"a-b=";c4.display2();return 0;
}
4-2 电子时钟中的运算符重载
#include <iostream>
#include <cstdio>
using namespace std;
class Time
{
private:int hour;int minute;int second;
public:Time(int h,int m,int s){hour=h;minute=m;second=s;}Time operator ++ ();void display();int cmp(Time &t);
};Time Time::operator ++ ( )
{if(++second>= 60){second-= 60;if(++minute>= 60){minute-=60;++hour;}}
}
void Time::display()
{printf ( "%.2d:%.2d:%.2d\n", hour, minute, second );
}
int Time::cmp(Time & t)
{if(hour>t.hour)return 0;else if(hour== t.hour&& minute > t.minute)return 0;else if(hour == t.hour && minute == t.minute && second > t.second)return 0;elsereturn 1;
}int main()
{int h1,h2,m1,m2,s1,s2;cin>>h1>>m1>>s1;cin>>h2>>m2>>s2;Time t1(h1,m1,s1);Time t2(h2,m2,s2);if(!t1.cmp(t2) ){cout<<"The begin time is not earlier than the end time!"<<endl;}else{while(t1.cmp(t2)){t1.display();++t1;}}return 0;
}面向对象程序设计上机练习十（运算符重载）
#include <iostream>
using namespace std;
class Complex
{
public:Complex(double a=0,double b=0){real=a,imag=b;}Complex operator +(Complex &a){return Complex(a.real+real,a.imag+imag);}Complex operator +(int a){return Complex(a+real,imag);}friend ostream &operator<<(ostream &o,Complex a){o<<a.real;if(a.imag>0) o<<"+";if(a.imag) o<<a.imag<<"i";o<<endl;return o;}friend Complex operator + (int a,Complex &b);
private:double real,imag;};
Complex operator + (int a,Complex &b)
{return Complex(a+b.real,b.imag);
}
int main()
{int a,b;cin>>a>>b;Complex c1(a,b);cin>>a>>b;Complex c2(a,b);cin>>a;cout<<c1+c2<<c1+a<<a+c1<<endl;return 0;
}面向对象程序设计上机练习十一（运算符重载）
#include <iostream>using namespace std;class position
{
private:int x1,x2,x3;int y1,y2,y3;public:position(int a=0,int b=0,int c=0,int d=0,int e=0,int f=0){x1=a;x2=b;x3=c;y1=d;y2=e;y3=f;}position operator +(position & r);friend ostream&operator <<(ostream&, position&);
};position position :: operator +(position & r)
{position p;p.x1=x1+r.x1;p.x2=x2+r.x2;p.x3=x3+r.x3;p.y1=y1+r.y1;p.y2=y2+r.y2;p.y3=y3+r.y3;return p;
}ostream & operator << (ostream & output, position &r)
{output<<r.x1<<" "<<r.x2<<" "<<r.x3<<endl;output<<r.y1<<" "<<r.y2<<" "<<r.y3;return output;
}int main()
{int a,b,c,d,e,f;cin>>a>>b>>c>>d>>e>>f;position r1(a,b,c,d,e,f);cin>>a>>b>>c>>d>>e>>f;position r2(a,b,c,d,e,f);position r3;r3=r1+r2;cout<<r3<<endl;return 0;
}面向对象程序设计上机练习十二（运算符重载）
#include <iostream>
#include <bits/stdc++.h>
using namespace std;
class Complex
{double real,imag;
public:operator double(){return real;}Complex (double a=0,double b=0){real=a;imag=b;}
};
int main()
{double a,b,c;cin>>a>>b>>c;Complex c1(a,b);double d=c1+c;cout<<fixed<<setprecision(1)<<d<<endl;return 0;
}
3-1 Point类的构造函数
#include <algorithm>
#include <iostream>
using namespace std;class point
{
private:int x, y;
public:point(){x = 0;y = 0;}void showpoint(){cout<<"("<<x<<","<<y<<")"<<endl;}void show(int a,int b){x = a;y = b;}
};int main()
{point p;int a, b;cin>>a>>b;p.showpoint();point p1;p1.show(a, b);p1.showpoint();return 0;
}3-2 构造函数的调用
#include <algorithm>
#include <iostream>
using namespace std;class point
{
public:void show(){cout<<"Constructing an object of A"<<endl;}~point(){cout<<"Destructing an object of A"<<endl;}
};int main()
{point A, B;A.show();B.show();return 0;
}
3-3 构造函数的调用(高级)
#include <algorithm>
#include <iostream>
using namespace std;class point
{
public:void show(){cout<<"constructing an object of A"<<endl;}~point(){cout<<"Destructing an object of A"<<endl;}
};void display()
{point C;C.show();
}int main()
{cout << "----begin main---" << endl;point A, B, D;A.show();display();cout << "*******"<<endl;B.show();D.show();cout << "----end main---" << endl;return 0;
}
3-4 计算长方形的周长和面积
#include <iostream>using namespace std;class Rect
{public:Rect(double L=0,double W=0){Length=L;Width=W;}void f1(){cout<<"the length and width of r1 is:"<<Length<<","<<Width<<endl;cout<<"the perimeter of r1 is:"<<2*(Length+Width)<<endl;cout<<"the area of r1 is:"<<Length*Width<<endl;}void f2(){cout<<"the length and width of r2 is:"<<Length<<","<<Width<<endl;cout<<"the perimeter of r2 is:"<<2*(Length+Width)<<endl;cout<<"the area of r2 is:"<<Length*Width<<endl;}Rect(const Rect &b){Length=b.Length;Width=b.Width;}private:double Length;double Width;
};int main()
{double a,b;cin>>a>>b;if(a<0||b<0){a=0;b=0;}Rect r1(a,b),r2(r1);r1.f1();r2.f2();return 0;
}3-5 学生成绩统计
#include <cstdio>
#include <algorithm>
#include <iostream>
using namespace std;class student
{
private:char name[50];int num;int math;int eng;int com;
public:void set_stu(student p[], int n){int i;for ( i = 0;i < n; i++ )cin>>p[i].num>>p[i].name>>p[i].math>>p[i].eng>>p[i].com;}int sum(student p){int Sum = 0;Sum = p.math+p.com+p.eng;return Sum;}double ave(int Sum){double Ave;Ave = (double)Sum/(double)3;return Ave;}void Printf(student p[]){cout<<"StuID"<<"\t"<<"Name"<<"\t"<<"Math"<<"\t"<<"Eng"<<"\t"<<"Com"<<"\t"<<"Total"<<"\t"<<"Average"<<endl;int i;for ( i = 0;i < 5; i++ ){int Sum;double Ave;Sum = sum(p[i]);Ave = ave(Sum);cout<<p[i].num<<"\t"<<p[i].name<<"\t"<<p[i].math<<"\t"<<p[i].eng<<"\t"<<p[i].com<<"\t"<<Sum<<"\t";printf ( "%.1lf\n", Ave );}}
};int main()
{cout<<"Input the messages of five students(StudentID Name Math English Computer )"<<endl<<endl;student stu[5];stu[5].set_stu(stu, 5);stu[5].Printf(stu);return 0;
}
3-6 静态数据成员与静态成员函数
#include <algorithm>
#include <iostream>
using namespace std;class point
{
private:double x, y;static int count;
public:static void showpoint();void display(){cout<<"Deconstructor point x=" << x << endl;}point(double a = 0, double b = 0){count++;x=a;y=b;}
};int point::count = 0;
void point::showpoint()
{cout << "x=0,Y=0" << endl;cout << "the number of points is " << count << endl;
}int main()
{point a(5), b(3), c(0);point::showpoint();a.display();b.display();c.display();return 0;
}3-7 类的友元函数的应用
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <iostream>
using namespace std;class point
{
private:double x;double y;
public:void display2(point &q);void display1(){cout<<" point is the coordinate:X="<<x<<","<<"Y="<<y<<endl;}point(double a, double b){x = a;y = b;}
};void point::display2(point &q)
{cout<<"The distance between the two points is:"<<sqrt((x-q.x)*(x-q.x)+(y-q.y)*(y-q.y))<<endl;
}int main()
{double a, b, c, d;cin>>a>>b>>c>>d;point x(a, b);point y(c, d);cout<<"The first";x.display1();cout<<"The second";y.display1();x.display2(y);return 0;
}面向对象程序设计上机练习八（对象数组）
#include <iostream>
#include <algorithm>
using namespace std;class student
{
private:int i;int num[1000], n;char name[1000][20];
public:void setint();void setput();
};void student::setint()
{cin>>n;for ( i = 0; i < n; i++ ){cin>>name[i]>>num[i];}
}void student::setput()
{for ( i = 0; i < n; i++ ){cout << name[i]<<" "<<num[i]<<endl;}
}int main()
{student t;t.setint();t.setput();
}面向对象程序设计上机练习九（对象指针）
#include <iostream>
#include <algorithm>
using namespace std;class student
{
private:int i;int k;int num[1000], n;char name[1000][20];
public:void setint();void setput();
};void student::setint()
{for ( i = 0; i < 5; i++ ){cin>>name[i]>>num[i];}
}void student::setput()
{int max = 0;for ( i = 0; i < 5; i++ ){if ( max < num[i] ){max = num[i];k = i;}}cout<<name[k]<<" "<<num[k]<<endl;
}int main()
{student t, *p;p = &t;(*p).setint();(*p).setput();return 0;
}