定義分數類運算子的重載

/** Copyright (c) 2013, 煙台大學電腦學院* All rights reserved.* 檔案名稱:text.cpp* 作者：胡穎* 完成日期:2013年4月27日* 版本號碼：v1.0** 輸入描述：無* 問題描述:定義分數類，利用成員函數實現分數的加、減、乘、除、輸入、輸出、運算* 程式輸出：輸出分數的運算結果* 問題分析：* 演算法設計：略*/#include <iostream>#include<cmath>using namespace std;class CFraction{private:      int nume;//分子      int deno;//分母public:      CFraction (int nu=0,int de=1):nume(nu),deno(de){ }      void simplify();      friend ostream&operator<<(ostream &,CFraction &);      friend istream&operator>>(istream &,CFraction &);      CFraction operator+(const CFraction &c);      CFraction operator-(const CFraction &c);      CFraction operator*(const CFraction &c);      CFraction operator/(const CFraction &c);      CFraction operator+();      CFraction operator-();      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);};void CFraction::simplify(){    int m,n,r;    m=fabs(deno);//取絕對值    n=fabs(nume);    while(r=m%n)    {        m=n;        n=r;    }    deno/=n;    nume/=n;    if(deno<0)    {        deno=-deno;        nume=-nume;    }}CFraction CFraction::operator+(const CFraction &c){    CFraction t;    t.deno=deno*c.deno;    t.nume=nume*c.deno+c.nume*deno;    t.simplify();    return t;}CFraction CFraction::operator-(const CFraction &c){    CFraction t;    t.deno=deno*c.deno;    t.nume=nume*c.deno-c.nume*deno;    t.simplify();    return t;}CFraction CFraction::operator*(const CFraction &c){    CFraction t;    t.deno=deno*c.deno;    t.nume=nume*c.nume;    t.simplify();    return t;}CFraction CFraction::operator/(const CFraction &c){    CFraction t;    if(!c.deno) return *this;    t.deno=deno*c.nume;    t.nume=nume*c.deno;    t.simplify();    return t;}CFraction CFraction::operator+(){    return *this;}CFraction CFraction::operator-(){    CFraction t;    t.deno=-deno;    t.nume=-nume;    return t;}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)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){    int this_nume,c_nume,common_deno;    this_nume=nume*c.deno;    c_nume=c.nume*deno;    common_deno=deno*c.deno;    if((this_nume-c_nume)*common_deno>0)return true;    return false;}bool CFraction::operator<(const CFraction &c){     int this_nume,c_nume,common_deno;    this_nume=nume*c.deno;    c_nume=c.nume*deno;    common_deno=deno*c.deno;    if((this_nume-c_nume)*common_deno<0)return true;    return false;}ostream&operator<<( ostream &output,CFraction &c){    output<<c.nume<<"/"<<c.deno<<endl;    return output;}istream&operator>>( istream&input,CFraction &c){    cout<<"請輸入分數："<<endl;    input>>c.nume>>c.deno;    return input;}int main(){   CFraction x,y,s;   cin>>x>>y;   cout<<"x="<<x;   cout<<"y="<<y;    s=+x+y;    cout<<"+x+y="<<s;    s=x-y;    cout<<"x-y="<<s;    s=x*y;    cout<<"x*y="<<s;    s=x/y;    cout<<"x/y="<<s;    s=-x+y;    cout<<"-x+y="<<s;    cout<<x;    if (x>y) cout<<"大於"<<endl;    if (x<y) cout<<"小於"<<endl;    if (x==y) cout<<"等於"<<endl;    cout<<y;    cout<<endl;    return 0;}

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