练习题1
解题思路：题目中描述是非成员，非友元的普通函数，又要实现复数的运算。第一感觉应该把real和imag设置成public，但是这样就破坏了C++的封装性，所以，我设置了一个getReal()和getImag()的函数，获取real和imag数据
//类声明文件
#include<iostream>
using namespace std;
class Complex
{
public:
//构造函数
Complex();
//构造构造函数
Complex(int ,int );
int getReal();
int getImag();
void display();
private:
int real;
int imag;
};
//类实现文件
#include<iostream>
#include "complex.h"
using namespace std;
Complex::Complex():real(0),imag(0){}
Complex::Complex(int r,int i):real(r),imag(i){}
int Complex::getReal()
{
return this->real;
}
int Complex::getImag()
{
return this->imag;
}
void Complex::display()
{
cout<<this->real<<" + "<<this->imag<<"i"<<endl;
}
//主函数文件
#include<iostream>
#include "complex.h"
using namespace std;
Complex operator +( Complex &complex1, Complex &complex2)
{
return (Complex(complex1.getReal()+complex2.getReal(),complex1.getImag()+complex2.getImag()));
}
int main()
{
class Complex complex1(3,30),complex2(5,20);
Complex complex3 = complex1 + complex2;
complex3.display();
system("pause");
return 0;
}
练习题2
//类声明文件
#include<iostream>
using namespace std;
class Complex
{
public:
//构造函数
Complex();
//构造构造函数
Complex(int ,int );
Complex operator +( Complex &complex);
Complex operator -( Complex &complex);
Complex operator *( Complex &complex);
Complex operator /( Complex &complex);
int getReal();
int getImag();
void display();
private:
int real;
int imag;
};
//类实现文件
#include<iostream>
#include "complex.h"
using namespace std;
Complex::Complex():real(0),imag(0){}
Complex::Complex(int r,int i):real(r),imag(i){}
Complex Complex::operator +( Complex &complex)
{
return (Complex(this->real + complex.real,this->imag + complex.imag));
}
Complex Complex::operator -( Complex &complex)
{
return (Complex(this->real - complex.real,this->imag - complex.imag));
}
Complex Complex::operator *( Complex &complex)
{
return (Complex(this->real * complex.real - this->imag * complex.imag,this->real * complex.imag + this->imag * complex.real));
}
Complex Complex::operator /( Complex &complex)
{
int Denominator = complex.real * complex.real + complex.imag * complex.imag;
if(Denominator != 0)
{
return (Complex((this->real * complex.real + this->imag * complex.imag)/Denominator,(this->imag * complex.real - this->real * complex.imag)/Denominator));
}
}
int Complex::getReal()
{
return this->real;
}
int Complex::getImag()
{
return this->imag;
}
void Complex::display()
{
cout<<this->real<<" + "<<this->imag<<"i"<<endl;
}
//主函数文件
#include<iostream>
#include "complex.h"
using namespace std;
int main()
{
class Complex complex1(3,30),complex2(5,20);
Complex complex3 = complex1 + complex2;
complex3.display();
Complex complex4 = complex1 - complex2;
complex4.display();
Complex complex5 = complex1 * complex2;
complex5.display();
Complex complex6 = complex1 / complex2;
complex6.display();
system("pause");
return 0;
}
练习题3
解题思路：根据题目描述，可以决定采用友元函数+转换构造函数可以实现加法交换律
//类声明文件
#include<iostream>
using namespace std;
class Complex
{
public:
//构造函数
Complex();
//构造构造函数
Complex(int ,int );
//转换构造函数
Complex(int );
friend Complex operator +( const Complex &,const Complex &);
int getReal();
int getImag();
void display();
private:
int real;
int imag;
};
//类实现文件
#include<iostream>
#include "complex.h"
using namespace std;
Complex::Complex():real(0),imag(0){}
Complex::Complex(int r):real(r),imag(0){}// 转换构造函数
Complex::Complex(int r,int i):real(r),imag(i){}
Complex operator +( const Complex &complex1,const Complex &complex2)
{
return (Complex(complex1.real + complex2.real,complex1.imag + complex2.imag));
}
int Complex::getReal()
{
return this->real;
}
int Complex::getImag()
{
return this->imag;
}
void Complex::display()
{
cout<<this->real<<" + "<<this->imag<<"i"<<endl;
}
//主函数文件
#include<iostream>
#include "complex.h"
using namespace std;
int main()
{
class Complex complex1(3,30),complex2(5,20);
Complex complex3 = complex1 + complex2;
complex3.display();
complex3 = 2 + complex2;
complex3.display();
complex3 = complex2 + 2;
complex3.display();
system("pause");
return 0;
}
练习题4+5
解题思路：在矩阵中我用了二维数组指针，同时还用了指针的指针。在析构函数中释放指针的指针，在浅拷贝中容易造成野指针，所以我使用了复制构造函数，解决上述问题。
指针的指针接收指针数组的过程，参考博客：https://blog.csdn.net/ChaoFeiLi/article/details/103674308
//类声明文件
#include<iostream>
using namespace std;
class Matrix
{
public:
Matrix(int = 1,int = 1);
Matrix(const Matrix&);
friend Matrix operator +(const Matrix&,const Matrix&);
friend ostream& operator <<(ostream&,const Matrix&);
friend istream& operator >>(istream&,const Matrix&);
void set();
void set(double **,int,int);
void display();
~Matrix(){
delete []ptr;
}
protected:
float **ptr;
private:
int row;
int column;
};
//类实现文件
#include<iostream>
#include "matrix.h"
using namespace std;
Matrix::Matrix(int r ,int c)
{
if(r ==0 || c == 0)
{
return;
}
row = r;
column = c;
ptr = new float* [row];
for(int i = 0; i < row; i++)
{
ptr[i] = new float [column];
}
}
Matrix::Matrix(const Matrix&matrix)
{
this->row = matrix.row;
this->column = matrix.column;
this->ptr = new float*[row];
for(int i = 0;i<row;i++)
{
ptr[i] = new float[column];
for(int j = 0;j<column;j++)
{
this->ptr[i][j] = matrix.ptr[i][j];
}
}
}
Matrix operator +(const Matrix &matrix1,const Matrix &matrix2)
{
int row = matrix1.row;
int column = matrix1.column;
Matrix matrix(row,column);
for(int i = 0;i < row;i++)
{
for(int j = 0;j < column;j++)
{
matrix.ptr[i][j] = matrix1.ptr[i][j] + matrix2.ptr[i][j];
}
}
return matrix;
}
ostream& operator <<(ostream &output,const Matrix &matrix)
{
int row = matrix.row;
int column = matrix.column;
for(int i = 0;i < row;i++)
{
for(int j = 0;j < column;j++)
{
output<<matrix.ptr[i][j]<<" ";
}
output<<endl;
}
return output;
}
istream& operator >>(istream& input,const Matrix&matrix)
{
int row = matrix.row;
int column = matrix.column;
for(int i = 0;i < row;i++)
{
for(int j = 0;j < column;j++)
{
input>>matrix.ptr[i][j];
}
}
return input;
}
void Matrix::set()
{
for(int i = 0;i < row;i++)
{
for(int j = 0;j < column;j++)
{
cin>>ptr[i][j];
}
}
}
void Matrix::set(double **p,int r,int c)
{
ptr = new float *[row];
for (int i = 0;i < row;i++)
{
ptr[i] = new float[column];
for (int j = 0;i<column;j++)
{
ptr[i][j] = p[i][j];
}
}
}
void Matrix::display()
{
for(int i = 0;i < row;i++)
{
for(int j = 0;j < column;j++)
{
cout<<ptr[i][j]<<" ";
}
cout<<endl;
}
}
//主函数文件
#include<iostream>
#include "matrix.h"
using namespace std;
int main()
{
Matrix matrix1(2,3);
cin>>matrix1;
cout<<endl;
Matrix matrix2(2,3);
cin>>matrix2;
Matrix matrix = matrix1 + matrix2;
cout<<matrix;
system("pause");
return 0;
}
练习题6
//类声明文件
#include<iostream>
using namespace std;
class Complex
{
public:
//构造函数
Complex();
//构造构造函数
Complex(double,double);
//转换构造函数
Complex(double);
//类型转换函数
operator double() const;
void display();
private:
double real;
double imag;
};
//类实现文件
#include<iostream>
#include "complex.h"
using namespace std;
Complex::Complex():real(0),imag(0){}
Complex::Complex(double r):real(r),imag(0){}
Complex::Complex(double r,double i):real(r),imag(i){}
void Complex::display()
{
cout<<this->real<<" + "<<this->imag<<"i"<<endl;
}
Complex::operator double() const
{
return this->real;
}
//主函数文件
#include<iostream>
#include "complex.h"
using namespace std;
int main()
{
class Complex complex1(3,30);
double d1 = 2.5;
d1 = d1 + complex1;
cout<<d1<<endl;
Complex(d1).display();
system("pause");
return 0;
}
练习题7
必须把class Student中的成员变量设置为public的，或者通过get函数获取；在转换构造函数中无法使用
//类声明文件
#include <iostream>
class Student
{
public:
Student(int,char [],char);
void display();
int num;
char name[50];
char sex;
};
class Teacher
{
public:
Teacher(int,char [],char);
//转换构造函数
Teacher(const Student&);
void display();
private:
int num;
char name[50];
char sex;
};
//类实现文件
#include <iostream>
#include "worker.h"
using namespace std;
Student::Student(int n,char na[],char s)
{
this->num = n;
strcpy(this->name, na);
this->sex = s;
}
void Student::display()
{
cout <<name<<endl;
}
Teacher::Teacher(int n,char na[],char s)
{
this->num = n;
strcpy(this->name, na);
this->sex = s;
}
Teacher::Teacher(const Student &student)
{
this->num = student.num;
strcpy(this->name, student.name);
this->sex = student.sex;
}
void Teacher::display()
{
cout<<this->name<<" "<<this->num<<" "<<this->sex<<endl;
}
//主函数文件
#include<iostream>
#include "worker.h"
using namespace std;
int main()
{
class Student student1(2017,"andrew",'m');
student1.display();
class Teacher teacher1(student1);
teacher1.display();
system("pause");
return 0;
}
