第九周上机实践项目3——分数类中的运算符重载（续）

在分数类中的运算符重载基础上
（1）定义分数的一目运算+和-，分别代表分数取正和求反，将“按位取反运算符”~重载为分数的求倒数运算。
（2）定义分数类中<<和>>运算符重载，实现分数的输入输出，改造原程序中对运算结果显示方式，使程序读起来更自然。

代码

/* * Copyright (c) 2015, 烟台大学计算机学院 * All rights reserved. * 文件名称：test.cpp * 作    者：辛彬 * 完成日期：2015 年 5 月 8 日 * 版 本 号：v1.0 */#include<iostream>using namespace std;class CFraction{private:    int nume;  // 分子    int deno;  // 分母public:    //构造函数及运算符重载的函数声明    CFraction() {}    CFraction(int n,int d):nume(n),deno(d) {}    void simplify();    CFraction operator+(CFraction &c);    CFraction operator+();    friend CFraction operator+(CFraction &c,int a);    friend CFraction operator+(int a,CFraction &c);    CFraction operator-(CFraction &c);    CFraction operator-();    CFraction operator~();    friend CFraction operator-(CFraction &c,int a);    friend CFraction operator-(int a,CFraction &c);    CFraction operator*(CFraction &c);    friend CFraction operator*(CFraction &c,int a);    friend CFraction operator*(int a,CFraction &c);    CFraction operator/(CFraction &c);    friend CFraction operator/(CFraction &c,int a);    friend CFraction operator/(int a,CFraction &c);    bool operator>(CFraction &c);    bool operator<(CFraction &c);    bool operator==(CFraction &c);    bool operator>=(CFraction &c);    bool operator<=(CFraction &c);    bool operator!=(CFraction &c);    friend ostream& operator<<(ostream&,const CFraction&);    friend istream& operator>>(istream&,CFraction&);};//重载函数的实现及用于测试的main()函数void CFraction::simplify(){    int i=deno;    for(; nume%i!=0||deno%i!=0; i--);    nume=nume/i;    deno=deno/i;}CFraction CFraction::operator+(CFraction &c){    int i=deno;    if(deno==c.deno)        return CFraction(nume+c.nume,deno);    else    {        for(; i%deno!=0||i%c.deno!=0; i++);        nume=nume*(i/deno);        c.nume=c.nume*(i/c.deno);        deno=i;        c.deno=i;        return CFraction(nume+c.nume,deno);    }}CFraction operator+(CFraction &c,int a){    CFraction t(a,1);    return c+t;}CFraction operator+(int a,CFraction &c){    CFraction t(a,1);    return c+t;}CFraction operator-(CFraction &c,int a){    CFraction t(a,1);    return c-t;}CFraction operator-(int a,CFraction &c){    CFraction t(a,1);    return c-t;}CFraction operator*(CFraction &c,int a){    CFraction t(a,1);    return c*t;}CFraction operator*(int a,CFraction &c){    CFraction t(a,1);    return c*t;}CFraction operator/(CFraction &c,int a){    CFraction t(a,1);    return c*t;}CFraction operator/(int a,CFraction &c){    CFraction t(a,1);    return c/t;}CFraction CFraction::operator-(CFraction &c){    int i=deno;    if(deno==c.deno)        return CFraction(nume-c.nume,deno);    else    {        for(; i%deno!=0||i%c.deno!=0; i++);        nume=nume*(i/deno);        c.nume=c.nume*(i/c.deno);        deno=i;        c.deno=i;        return CFraction(nume-c.nume,deno);    }}CFraction CFraction::operator*(CFraction &c){    return CFraction(nume*c.nume,deno*c.deno);}CFraction CFraction::operator/(CFraction &c){    if(deno*c.nume<0)        return CFraction(-nume*c.deno,-deno*c.nume);    else        return CFraction(nume*c.deno,deno*c.nume);}bool CFraction::operator>(CFraction &c){    int i=deno;    if(deno==c.deno)    {        if(nume>c.nume)            return true;        else            return false;    }    else    {        for(; i%deno!=0||i%c.deno!=0; i++);        nume=nume*(i/deno);        c.nume=c.nume*(i/c.deno);        if(nume>c.nume)            return true;        else            return false;    }}bool CFraction::operator<(CFraction &c){    int i=deno;    if(deno==c.deno)    {        if(nume<c.nume)            return true;        else            return false;    }    else    {        for(; i%deno!=0||i%c.deno!=0; i++);        nume=nume*(i/deno);        c.nume=c.nume*(i/c.deno);        if(nume<c.nume)            return true;        else            return false;    }}bool CFraction::operator==(CFraction &c){    if(*this>c||*this<c)        return false;    else return true;}bool CFraction::operator>=(CFraction &c){    return !(*this<c);}bool CFraction::operator<=(CFraction &c){    return !(*this>c);}bool CFraction::operator!=(CFraction &c){    return !(*this==c);}CFraction CFraction::operator+(){    if(nume<0)        nume=-nume;    return *this;}CFraction CFraction::operator-(){    nume=-nume;    return *this;}CFraction CFraction::operator~(){    CFraction t;    if(nume<0)    {        t.deno=-nume;        t.nume=-deno;    }    else    {        t.deno=nume;        t.nume=deno;    }    return t;}ostream& operator<<(ostream& out,const CFraction& c){    out<<c.nume<<"/"<<c.deno;    return out;}istream& operator>>(istream& in,CFraction& c){    cout<<"输入分子和分母:";    in>>c.nume>>c.deno;    return in;}int main(){    CFraction x(1,3),y(-5,10),s;    cout<<"分数x=1/3      y=-5/10"<<endl;    s=x+y;    cout<<"x+y=";    s.simplify();    cout<<s<<endl;    s=x-y;    cout<<"x-y=";    s.simplify();    cout<<s<<endl;    s=x*y;    cout<<"x*y=";    s.simplify();    cout<<s<<endl;    s=x/y;    cout<<"x/y=";    s.simplify();    cout<<s<<endl;    cout<<x<<endl;    if (x>y) cout<<"大于"<<endl;    if (x<y) cout<<"小于"<<endl;    if (x==y) cout<<"等于"<<endl;    cout<<y<<endl;    cout<<endl;    CFraction c1(5,3),c2,c3;    cout<<"c1="<<c1<<endl;    c2=c1+5;    cout<<"c1+5="<<c2<<endl;    c2=5+c1;    cout<<"5+c1="<<c2<<endl;    c2=c1-5;    cout<<"c1-5="<<c2<<endl;    c2=5-c1;    cout<<"5-c1="<<c2<<endl;    c2=c1*5;    cout<<"c1*5="<<c2<<endl;    c2=5*c1;    cout<<"5*c1="<<c2<<endl;    c2=c1/5;    cout<<"c1/5="<<c2<<endl;    c2=5/c1;    cout<<"5/c1="<<c2<<endl;    cin>>c3;    cout<<"+c3="<<+c3<<endl;    cout<<"-c3="<<-c3<<endl;    cout<<"~c3="<<~c3<<endl;    return 0;}

运行结果

学习感悟：发现前面两个定义了输入流，在测试函数里没有用到，于是现在加了上去