1088 Rational Arithmetic (20 分)

#include<bits/stdc++.h>
using namespace std;
#define ll long long
struct fraction
{
    ll up,down;
};

ll gcd(ll a,ll b)
{
    if(b==0) return a;
    else return gcd(b,a%b);
}

fraction reduction(fraction result)
{
    if(result.down<0)
    {
        result.down=-result.down;
        result.up=-result.up;

    }

    if(result.up==0)
    {
        result.down=1;
    }
    else
    {
        int d=gcd(abs(result.up),(result.down));
        result.down/=d;
        result.up/=d;

    }
    return result;
}

fraction add(fraction a,fraction b)
{

    fraction sum;
    sum.up=a.up*b.down+a.down*b.up;
    sum.down=a.down*b.down;
    return reduction(sum);


}
fraction minu(fraction a,fraction b)
{
    fraction ans;
    ans.down=a.down*b.down;
    ans.up=a.up*b.down-a.down*b.up;
    reduction(ans);
    return ans;
}

fraction multi(fraction a,fraction b)
{
    fraction ans;
    ans.down=a.down*b.down;
    ans.up=a.up*b.up;
    reduction(ans);
    return ans;
}
fraction divide(fraction a,fraction b)
{

    fraction ans;
    ans.down=a.down*b.up;
    ans.up=a.up*b.down;
    reduction(ans);
    return ans;


}
void showresult(fraction r)
{
    r=reduction(r);
    if(r.down==1)
    {
        if(r.up<0)
        {
            printf("(%lld)",r.up);
        }
        else
            printf("%lld",r.up);
    }
    else if(abs(r.up)>r.down)
    {
        if(r.up<0)
        {
            printf("(%lld %lld/%lld)",r.up/r.down,abs(r.up)%r.down,r.down);
        }
        else
            printf("%lld %lld/%lld",r.up/r.down,abs(r.up)%r.down,r.down);
    }
    else
    {
        if(r.up<0)
        {
            printf("(%lld/%lld)",r.up,r.down);
        }
        else
            printf("%lld/%lld",r.up,r.down);
    }
}
int main()
{


    fraction a,b;
    scanf("%lld/%lld",&a.up,&a.down);
    scanf("%lld/%lld",&b.up,&b.down);

    reduction(a);
    reduction(b);

    fraction ans1=add(a,b);
    showresult(a);
    printf(" + ");
    showresult(b);
    printf(" = ");
    showresult(ans1);
    printf("\n");
//
    fraction ans2=minu(a,b);
    showresult(a);
    printf(" - ");
    showresult(b);
    printf(" = ");
    showresult(ans2);
    printf("\n");
    fraction ans3=multi(a,b);
    showresult(a);
    printf(" * ");
    showresult(b);
    printf(" = ");
    showresult(ans3);
    printf("\n");



    showresult(a);
    printf(" / ");
    showresult(b);
    printf(" = ");
    if(b.up==0)
    {
        printf("Inf\n");
    }
    else
    {
        fraction ans4=divide(a,b);
        showresult(ans4);
    }

}