#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <assert.h>


#define ABC(x) ((x) < 0 ? -(x) : (x))

typedef struct
{
    int32_t num, denom;
} Ratio;

int32_t Gcd(int32_t a, int32_t b){
    int32_t t;
    while (b != 0) {
        t = b;
        b = a % b;
        a = t;
    }
    return a;
}

//int32_t lcm(int32_t a, int32_t b){
//   int32_t g = gcd(a, b);
//   if(g == 0){
//       return 1;
//   }
//   else {
//       return (a * b) / g;
//   }
//}

Ratio Normalization(Ratio r){
    int32_t a = Gcd( ABC(r.num), ABC(r.denom) );

    r.denom /= a;
    r.num   /= a;

    return r;
}

void Input(Ratio *pR)
{
    assert(pR);

    printf("Enter ration(num denom): ");
    scanf(" %d %d", &pR->num, &pR->denom);
    while(pR->denom == 0){
        printf("The denominator cannot be equal to 0, try again: ");
        scanf(" %d %d", &pR->num, &pR->denom);
    }

    if(pR->denom < 0){
        pR->num   *= -1;
        pR->denom *= -1;
    }

    *pR = Normalization(*pR);

}

void Output(const Ratio r)
{
    printf("%d/%d\n", r.num, r.denom);
}

int Cmp(const Ratio left, const Ratio right) {
    int32_t g = Gcd(ABC(left.denom), ABC(right.denom));

    if((left.num * right.denom / g) < (right.num * left.denom / g )){
        return -1;
    }
    else if((left.denom == right.denom) && (left.num && right.num)){
        return 0;
    }
    else {
        return 1;
    }
}

Ratio Sum(Ratio left, Ratio right) {
    int32_t g = Gcd(ABC(left.denom), ABC(right.denom));
    left.num *= right.denom / g;
    right.num *= left.denom / g;

    Ratio sum;
    sum.num   = left.num + right.num;
    sum.denom = left.denom * right.denom / g;

    return Normalization(sum);
}

Ratio Sub(Ratio left, Ratio right) {
    int32_t g = Gcd(ABC(left.denom), ABC(right.denom));
    left.num *= right.denom / g;
    right.num *= left.denom / g;

    Ratio sub;
    sub.num   = left.num - right.num;
    sub.denom = left.denom * right.denom / g;

    return Normalization(sub);
}

Ratio Multi(Ratio left, Ratio right) {
    Ratio multi;
    multi.num   = left.num * right.num;
    multi.denom = left.denom * right.denom;

    return Normalization(multi);
}

Ratio Div(Ratio left, Ratio right) {
    Ratio div;
    div.num   = left.num * right.denom;
    div.denom = left.denom * right.num;

    return Normalization(div);
}

int main()
{
    Ratio r;
    Input(&r);
    Output(r);

    Ratio r2;
    Input(&r2);
    Output(r2);

    printf("cmp(r, r2): %d\n", Cmp(r, r2));

    printf("\nSum: "); Output( Sum(r, r2) );
    printf("\nSub: "); Output( Sub(r, r2) );
    printf("\nMulti: "); Output( Multi(r, r2) );
    printf("\nDiv: "); Output( Div(r, r2) );


    return 0;
}