第9周-运算符重载(二)-分数类中的运算符重载(续)

/* 
* Copyright (c) 2014, 烟台大学计算机学院 
* All rights reserved. 
* 文件名称：test.cpp 
* 作    者：刘畅 
* 完成日期：2015 年 5  月  6 日 
* 版 本 号：v1.0 
* 
* 问题描述：在第八周项目3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。
* 输入描述： 输入c2；
* 程序输出： 按要求输出。

代码如下：

#include <iostream>
using namespace std;
int gcd(int x, int y);
class CFraction
{
private:
    int nume;
    int deno;
public:
    CFraction(int n=0,int d=1)
    {
        nume=n;
        deno=d;
    }
    void simplify();

    CFraction operator+(const CFraction &c);
    CFraction operator-(const CFraction &c);
    CFraction operator*(const CFraction &c);
    CFraction operator/(const CFraction &c);

    bool operator>(const CFraction &c);
    bool operator<(const CFraction &c);
    bool operator==(const CFraction &c);
    bool operator!=(const CFraction &c);
    bool operator>=(const CFraction &c);
    bool operator<=(const CFraction &c);

    friend istream &operator>>(istream &input,CFraction &c);
    friend ostream &operator<<(ostream &output,CFraction &c);

    CFraction operator+();
    CFraction operator-();
    CFraction operator~();

};

void CFraction::simplify()
{
    int n=gcd(nume,deno);
    nume/=n;
    deno/=n;
}

int gcd(int x, int y)
{
    int z;
    while (y!=0)
    {
        z=x;
        x=y;
        y=z%y;
    }
    return x;

}

CFraction CFraction::operator+(const CFraction &c)
{
    CFraction c1;
    c1.nume=nume*c.deno+c.nume*deno;
    c1.deno=deno*c.deno;
    c1.simplify();
    return c1;
}

CFraction CFraction::operator-(const CFraction &c)
{
    CFraction c1;
    c1.nume=nume*c.deno-c.nume*deno;
    c1.deno=deno*c.deno;
    c1.simplify();
    return c1;
}

CFraction CFraction::operator*(const CFraction &c)
{
    CFraction c1;
    c1.nume=nume*c.nume;
    c1.deno=deno*c.deno;
    c1.simplify();
    return c1;
}

CFraction CFraction:: operator/(const CFraction &c)
{
    CFraction c1;
    if (c.nume == 0)
        return *this;
    c1.nume=nume*c.deno;
    c1.deno=deno*c.nume;
    c1.simplify();
    return c1;
}

bool CFraction::operator>(const CFraction &c)
{
    int t_nume,c_nume,common_deno;
    t_nume=nume*c.deno;
    c_nume=c.nume*deno;
    common_deno=deno*c.deno;
    if ((t_nume-c_nume)*common_deno>0)
        return true;
    return false;
}

bool CFraction::operator<(const CFraction &c)
{
    int t_nume,c_nume,common_deno;
    t_nume=nume*c.deno;
    c_nume=c.nume*deno;
    common_deno=deno*c.deno;
    if ((t_nume-c_nume)*common_deno<0)
        return true;
    return false;
}

bool CFraction::operator>=(const CFraction &c)
{

    if (*this<c)
        return false;
    return true;
}

bool CFraction::operator<=(const CFraction &c)
{

    if (*this>c)
        return false;
    return true;
}

bool CFraction::operator!=(const CFraction &c)
{

    if (*this<c||*this>c)
        return true;
    return false;
}

bool CFraction::operator==(const CFraction &c)
{

    if (*this!=c)
        return false;
    return true;
}

istream &operator>>(istream &input,CFraction &c)
{
    char ch;
    while(1)
    {
        cin>>c.nume>>ch>>c.deno;
        if (c.deno==0)
            cerr<<"分母为0, 请重新输入\n";
        else if(ch!='/')
            cerr<<"格式错误（形如m/n）! 请重新输入\n";
        else
            break;
    }
    return input;
}


ostream &operator<<(ostream &output,CFraction &c)
{
    if(c.deno<0)
    {
        c.deno=-c.deno;
        c.nume=-c.nume;
    }
    cout<<c.nume<<'/'<<c.deno<<endl;
    return cout;
}

CFraction CFraction::operator+()
{
    return *this;
}
CFraction CFraction::operator-()
{
    CFraction c;
    c.nume=-nume;
    c.deno=deno;

    return c;
}
CFraction CFraction::operator~()
{
    CFraction c;
    c.nume=deno;
    c.deno=nume;
    if(c.deno<0)
    {
        c.deno=-c.deno;
        c.nume=-c.nume;
    }
    return c;

}


int main()
{
    CFraction c1(10,5),c2,c3;
    cout<<"c1:"<<c1;
    c3=+c1;
    cout<<"+c1:";
    cout<<c3;
    c3=-c1;
    cout<<"-c1:";
    cout<<c3;
    c3=~c1;
    cout<<"~c1:";
    cout<<c3;
    cout<<"c2:";
    cin>>c2;
    cout<<c2;
    cout<<endl;

    c3=c1+c2;
    cout<<"c1+c2=";
    cout<<c3;
    c3=+c1+c2;
    cout<<"+c1+c2=";
    cout<<c3;

    c3=c1-c2;
    cout<<"c1-c2=";
    cout<<c3;
    c3=-c1-c2;
    cout<<"-c1-c2=";
    cout<<c3;

    c3=c1*c2;
    cout<<"c1*c2=";
    cout<<c3;
    c3=~c1*c2;
    cout<<"~c1*c2=";
    cout<<c3;

    c3=c1/c2;
    cout<<"c1/c2=";
    cout<<c3;
    cout<<endl;

    if (c1>c2)
        cout<<"c1>c2"<<endl;
    if (c1<c2)
        cout<<"c1<c2"<<endl;
    if (c1>=c2)
        cout<<"c1>=c2"<<endl;
    if (c1<=c2)
        cout<<"c1<=c2"<<endl;
    if (c1==c2)
        cout<<"c1==c2"<<endl;
    if (c1!=c2)
        cout<<"c1!=c2"<<endl;
    return 0;

}

运行结果：

学习心得：

好不容易理顺了之前写的代码，然后把要添加的内容写了进去，在定义求反，和求分数的导数时一定要重新定义一个对象，我之前用的原对象修改，然后return *this，对后面的其他计算造成了很大的影响，完全变了。