#include<iostream>
#include<cmath>
using namespace std;
class fraction{
int above;
//分子
int below;
//分母
void reduction();
//约分
void makeCommond(fraction&); //通分
public:
fraction(int a=0,int b=1){
//构造函数
above=a;below=b;
}
fraction add(fraction);
//两分数相加
fraction sub(fraction);
//本分数减去实参分数
fraction mul(fraction);
//两分数相乘
fraction div(fraction);
//本分数除以实参分数
fraction reciprocal();
//求倒数
bool equal(fraction);
//等于运算
bool greaterThan(fraction);
//大于运算
bool lessThan(fraction);
//小于运算
void display();
//显示分数
void input();
//输入分数
};
void fraction::reduction(){
//约分先求最大公约数
int a,b,temp;
if(below<0){
above=-above;
below=-below;
}
a=abs(above);
b=abs(below);
while(a%b){
//欧几里德法求最大公约数
temp=a;
a=b;
b=temp%b;
}
above/=b;
below/=b;
}
void fraction::makeCommond(fraction& b){
int temp;
reduction();
b.reduction();
above*=b.below;
b.above*=below;
temp=below*b.below;
below=b.below=temp;
}
fraction fraction::add(fraction b){
fraction temp;
makeCommond(b);
//通分
temp.above=above+b.above;
temp.below=below;
temp.reduction();
//约分
return temp;
}
fraction fraction::sub(fraction b){
fraction temp;
makeCommond(b);
//通分
temp.above=above-b.above;
temp.below=below;
temp.reduction();
//约分
return temp;
}
fraction fraction::mul(fraction b){
fraction temp;
temp.above=above*b.above;
temp.below=below*b.below;
temp.reduction();
//约分
return temp;
}
fraction fraction::div(fraction b){
fraction temp;
if(b.above==0){
cout<<"零不能作除数！"<<endl;
exit(1);
}
temp.above=above*b.below;
temp.below=below*b.above;
temp.reduction();
//约分
return temp;
}
fraction fraction::reciprocal(){
fraction temp;
temp.above=below;
temp.below=above;
temp.reduction();
//约分
return temp;
}
bool fraction::equal(fraction b){
makeCommond(b);
//通分
return(above==b.above);
}
bool fraction::greaterThan(fraction b){
makeCommond(b);
//通分
return(above>b.above);
}
bool fraction::lessThan(fraction b){
makeCommond(b);
//通分
return(above<b.above);
}
void fraction::display(){
reduction();
//约分
cout<<"为："<<above<<"/"<<below<<endl;
}
void fraction::input(){
while(1){
cout<<"请顺序输入分子和分母（整数）："<<endl;
cin>>above>>below;
if(below==0)
cout<<"分母不可为零！"<<endl;
else{
reduction();
return;
}
}
}
int main(){
fraction f1(-3,-5),f2(-3,5),f3(3,-7),f4,f5(8);
cout<<"f1"; f1.display();
cout<<"f2"; f2.display();
cout<<"f3"; f3.display();
cout<<"f4"; f4.display();
cout<<"f5"; f5.display();
if(f1.greaterThan(f2))
cout<<"f1>f2"<<endl;
if(f2.lessThan(f3))
cout<<"f2<f3"<<endl;
if(f1.equal(f1))
cout<<"f1==f1"<<endl;
f4=f1.add(f3);
cout<<"f4=f1+f3"; f4.display();
f4=f1.sub(f2);
cout<<"f4=f1-f2"; f4.display();
f4=f1.mul(f3);
cout<<"f4=f1*f3"; f4.display();
f4=f2.div(f3);
cout<<"f4=f1/f3"; f4.display();
f4=f2.reciprocal();
cout<<"f4=1/f2"; f4.display();
f4.input();
cout<<"f4"; f4.display();
return 0;
}
