问题及代码:
/*
*Copyright (c)2014,烟台大学计算机与控制工程学院
*All rights reserved.
*文件名称: 分数类中的运算符重载 .cpp
*作 者:白云飞
*完成日期:2015年4月25日
*版 本 号:v1.0
*
*问题描述:实现分数类中的运算符重载,在分数类中可以完成分数的加减乘除(运算后再化简)、比较(6种关系)的运算。实现分数类中的对象和整型数的四则运算。分数类中的对象可以和整型数进行四则运算,且运算符合交换律。
*程序输入:分子和分母
*程序输出:分数的各个形式
*/
#include <iostream>
#include<cmath>
#include<cstdlib>
using namespace std;
int gcd(int m, int n);
class CFraction
{
private:
int nume; // 分子
int deno; // 分母
public:
CFraction(int nu=0,int de=1); //构造函数,初始化用
CFraction operator+( CFraction &c);
CFraction operator-( CFraction &c);
CFraction operator*( CFraction &c);
CFraction operator/( CFraction &c);
friend CFraction operator+(const CFraction &c, int i);
friend CFraction operator+(int i, const CFraction &c );
friend CFraction operator-(const CFraction &c, int i);
friend CFraction operator-(int i, const CFraction &c );
friend CFraction operator*(const CFraction &c, int i);
friend CFraction operator*(int i, const CFraction &c );
friend CFraction operator/(const CFraction &c, int i);
friend CFraction operator/(int i, const 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 bool operator>(const CFraction &c, int i);
friend bool operator>(int i, const CFraction &c);
friend bool operator<(const CFraction &c, int i);
friend bool operator<(int i, const CFraction &c);
friend bool operator==(const CFraction &c, int i);
friend bool operator==(int i, const CFraction &c);
friend bool operator!=(const CFraction &c, int i);
friend bool operator!=(int i, const CFraction &c);
friend bool operator>=(const CFraction &c, int i);
friend bool operator>=(int i, const CFraction &c);
friend bool operator<=(const CFraction &c, int i);
friend bool operator<=(int i, const CFraction &c);
void input(); //按照"nu/de"的格式,如"5/2"的形式输入
void simplify(); //化简(使分子分母没有公因子)
void output();
};
CFraction::CFraction(int nu,int de)
{
if(de!=0)
{
nume=nu;
deno=de;
}
else
{
cerr<<"输入错误!";
exit(0);
}
}
CFraction CFraction::operator+( CFraction &c)
{
CFraction t;
t.nume=nume*c.deno+c.nume*deno;
t.deno=deno*c.deno;
t.simplify();
return t;
}
CFraction CFraction::operator-( CFraction &c)
{
CFraction t;
t.nume=nume*c.deno-c.nume*deno;
t.deno=deno*c.deno;
t.simplify();
return t;
}
CFraction CFraction::operator*( CFraction &c)
{
CFraction t;
t.nume=nume*c.nume;
t.deno=deno*c.deno;
t.simplify();
return t;
}
CFraction CFraction::operator/( CFraction &c)
{
CFraction t;
t.nume=nume*c.deno;
t.deno=deno*c.nume;
t.simplify();
return t;
}
CFraction operator+(const CFraction &c, int i)
{
CFraction t;
t.nume=i*c.deno+c.nume;
t.deno=c.deno;
t.simplify();
return t;
}
CFraction operator+(int i, const CFraction &c )
{
CFraction t;
t.nume=i*c.deno+c.nume;
t.deno=c.deno;
t.simplify();
return t;
}
CFraction operator-(const CFraction &c, int i)
{
CFraction t;
t.nume=c.nume-i*c.deno;
t.deno=c.deno;
t.simplify();
return t;
}
CFraction operator-(int i, const CFraction &c )
{
CFraction t;
t.nume=i*c.deno-c.nume;
t.deno=c.deno;
t.simplify();
return t;
}
CFraction operator*(const CFraction &c, int i)
{
CFraction t;
t.nume=i*c.nume;
t.deno=c.deno;
t.simplify();
return t;
}
CFraction operator*(int i, const CFraction &c )
{
CFraction t;
t.nume=i*c.nume;
t.deno=c.deno;
t.simplify();
return t;
}
CFraction operator/(const CFraction &c, int i)
{
CFraction t;
t.nume=c.nume;
t.deno=i*c.deno;
t.simplify();
return t;
}
CFraction operator/(int i, const CFraction &c )
{
CFraction t;
t.nume=i*c.deno;
t.deno=c.nume;
t.simplify();
return t;
}
bool CFraction::operator>(CFraction &c)
{
int nume1,nume2;
nume1=nume*c.deno;
nume2=c.nume*deno;
if(nume1-nume2>0) return true;
else return false;
}
bool CFraction::operator<(CFraction &c)
{
int nume1,nume2;
nume1=nume*c.deno;
nume2=c.nume*deno;
if(nume1-nume2<0) return true;
else return false;
}
bool CFraction::operator>=(CFraction &c)
{
return !(*this<c);
}
bool CFraction::operator<=(CFraction &c)
{
return !(*this>c);
}
bool CFraction::operator==(CFraction &c)
{
if(*this!=c) return false;
else return true;
}
bool CFraction::operator!=(CFraction &c)
{
if(*this>c||*this<c) return true;
else return false;
}
bool operator>(const CFraction &c, int i)
{
if(c.nume>i*c.deno)return true;
else return false;
}
bool operator>(int i, const CFraction &c)
{
if(i*c.deno>c.nume)return true;
else return false;
}
bool operator<(const CFraction &c, int i)
{
if(c.nume<i*c.deno)return true;
else return false;
}
bool operator<(int i, const CFraction &c)
{
if(i*c.deno<c.nume)return true;
else return false;
}
bool operator==(const CFraction &c, int i)
{
return c.nume==(i*c.deno);
}
bool operator==(int i, const CFraction &c)
{
return c.nume==(i*c.deno);
}
bool operator!=(const CFraction &c, int i)
{
return c.nume!=(i*c.deno);
}
bool operator!=(int i, const CFraction &c)
{
return c.nume!=(i*c.deno);
}
bool operator>=(const CFraction &c, int i)
{
return !(c<i);
}
bool operator>=(int i, const CFraction &c)
{
return !(c>i);
}
bool operator<=(const CFraction &c, int i)
{
return !(c>i);
}
bool operator<=(int i, const CFraction &c)
{
return !(c<i);
}
void CFraction::input()
{
int nu,de;
char m;
cout<<"请输入b分数(分子/分母):";
cin>>nu>>m>>de;
if(m!='/')
cout<<"输入格式错误";
else if(de==0)
cout<<"分母为零,输入错误.";
else
{
nume=nu;
deno=de;
}
}
void CFraction::simplify()
{
int n=gcd(deno, nume);
deno/=n; // 化简
nume/=n;
}
int gcd(int m, int n) //这个函数可以定义为类的成员函数,也可以为一般函数
{
int r;
if (m<n)
{
r=m;
m=n;
n=r;
}
while(r=m%n) // 求m,n的最大公约数
{
m=n;
n=r;
}
return n;
}
void CFraction::output()
{
cout<<"("<<nume<<"/"<<deno<<")"<<endl;
}
int main()
{
CFraction a(10,12),b,c;
cout<<"a=10/12 "<<endl;
b.input();
if (a>b) cout<<"a>b"<<endl;
if (a<b) cout<<"a<b"<<endl;
if (a>=b) cout<<"a>=b"<<endl;
if (a<=b) cout<<"a<=b"<<endl;
if (a==b) cout<<"a=b"<<endl;
if (a!=b) cout<<"a!=b"<<endl;
c=a+b;
cout<<"a+b=";
c.output();
c=a-b;
cout<<"a-b=";
c.output();
c=a*b;
cout<<"a*b=";
c.output();
c=a/b;
cout<<"a/b=";
c.output();
c=a+1;
cout<<"a+1=";
c.output();
c=1+a;
cout<<"1+a=";
c.output();
c=a-1;
cout<<"a-1=";
c.output();
c=1-a;
cout<<"1-a=";
c.output();
c=a*2;
cout<<"a*2=";
c.output();
c=2*a;
cout<<"2*a=";
c.output();
c=a/2;
cout<<"a/2=";
c.output();
c=2/a;
cout<<"2/a=";
c.output();
if (a>2) cout<<"a>2"<<endl;
if (a<2) cout<<"a<2"<<endl;
if (a>=2) cout<<"a>=2"<<endl;
if (a<=2) cout<<"a<=2"<<endl;
if (a==2) cout<<"a=2"<<endl;
if (a!=2) cout<<"a!=2"<<endl;
return 0;
}
运行结果:
学习心得:
在上一篇博客的基础上,这篇加了些内容,因为要实现在分数类中的对象和整数型的四则运算,所以就用了友元函数,bool型函数中用类的对象和整数比较也使用了友元函数。