1034. 有理数四则运算(20)

#include<iostream>
#include<iomanip>
#include<cmath>
using namespace std;

int main()
{
void output(long int a,long int b);
long int a1,b1,a2,b2;
long int c[4]={0},d[4]={0};
char sign[]={'+','-','*','/'};
scanf("%ld/%ld %ld/%ld",&a1,&b1,&a2,&b2);
c[0]=a1*b2+a2*b1;d[0]=b1*b2;
c[1]=a1*b2-a2*b1;d[1]=b1*b2;
c[2]=a1*a2;d[2]=b1*b2;
c[3]=a1*b2;d[3]=b1*a2;
if(d[3]<0){c[3]=-c[3];d[3]=-d[3];}
for(int i=0;i<4;i++)
{
if(a1==0){cout<<0;}else{output(a1,b1);}
cout<<" "<<sign[i]<<" ";
if(a2==0){cout<<0;}else{output(a2,b2);}
cout<<" = ";
if(i<3)
{
if(c[i]==0){cout<<0;}
else{output(c[i],d[i]);}
}else
{
if(d[3]==0){cout<<"Inf";}
else if(c[3]==0){cout<<0;}
else{output(c[3],d[3]);}
}
cout<<endl;
}
return 0;
}

void output(long int a,long int b)
{
long int gys(long int x,long int y);
bool f=false;
if(a<0){cout<<"(-";a=-a;f=true;}
long int g=gys(a,b);
a=a/g;b=b/g;
long int zs=a/b;
long int ys=a%b;
if(zs!=0)
{
cout<<zs;
if(ys!=0){cout<<" "<<ys<<"/"<<b;}
}
else{cout<<ys<<"/"<<b;}
if(f){cout<<")";}
}

long int gys(long int x,long int y)
{
long int r;
while(y>0)
{
r=x%y;
x=y;
y=r;
}
return x;
}