c++程序入门（三）——用结构和类分别实现复数加法和乘法

问题描述：分别使用结构和类编程实现复数加减法

/*使用复数结构，编写通用函数求两个复数的和和积*/struct complex{    int real;    int im;};struct complex cadd(struct complex c1,struct complex c2);struct complex cadd(struct complex c1,struct complex c2) //现在cadd是一个返回类型是struct complex的函数{    struct complex result;    result.real=c1.real+c2.real;    result.im=c1.im+c2.im;    return result;}struct complex cmult(struct complex c1, struct complex c2);struct complex cmult(struct complex c1, struct complex c2){    struct complex result;    result.real = c1.real*c2.real - c1.im*c2.im;    result.im = c1.real*c2.im + c1.im*c2.real;    return result;}//编写结果输出函数void puts(struct complex c);void puts(struct complex c){    cout<<c.real<<"+（"<<"i*"<<c.im<<")"<<endl;}int main(){    struct complex c1,c2,c3;    while(cin>>c1.real&&cin>>c1.im&&cin>>c2.real&&cin>>c2.im)    {        c3=cadd(c1,c2);        puts(c3);        c3=cmult(c1,c2);        puts(c3);    }    cin.get();}

/*用类来实现复数的加法和乘法*/class complex{public:    int real;    int im;//   complex(int m=0,int n=0);    void set_c(int m,int n);    void cadd(complex c1, complex c2);    void cmult(complex c1,complex c2);    void put();};//complex::complex(int m,int n)//{//  real = m;//  im = n;//}void complex::set_c(int m, int n){    real = m;     im = n;}void complex::cadd(complex c1, complex c2){    real = c1.real + c2.real;    im = c1.im + c2.im;}void complex::cmult(complex c1,complex c2){       real = c1.real*c2.real - c1.im*c2.im;    im = c1.real *c2.im + c2.real*c1.im;}void complex::put(){    cout<<real<<"+(i*"<<im<<")"<<endl;}int main(){    complex c1,c2,c3;    int r1,i1,r2,i2;    while(cin>>r1 && cin>>i1 &&cin>>r2 &&cin>>i2)    {        c1.set_c(r1,i1);        c1.put();        c2.set_c(r2,i2);        c2.put();        c3.cadd(c1,c2);        c3.put();        c3.cmult(c1,c2);        c3.put();    }    cin.get();}

用友元实现：

//*******用类和友元函数实现复数加减和乘除******/class complex{    float real;    float im;public:    complex(float m=0,float n=0);    void set_c(float m,float n);    //这里使用友元函数    friend complex cadd(complex c1,complex c2);    friend complex cmult(complex c1,complex c2);    void put();};complex cadd(complex c1,complex c2){    complex c3;    c3.real=c1.real+c2.real;    c3.im = c1.im+c2.im;    return c3;}complex cmult(complex c1,complex c2){    complex c3;    c3.real = c1.real*c2.real -c1.im*c2.im;    c3.im = c1.real*c2.im+c1.im*c2.real;    return c3;}