#include <stdio.h>
#include <stdlib.h>

typedef struct {
    int nat;  // natural (integer)
    int num;  // numerator
    int den;  // denominator
} Fraction;

void frPrint(Fraction f) {
    if (f.num != 0)
        if (f.nat == 0)
            printf("%d / %d", f.num, f.den);
        else
            printf("%d %d/%d",f.nat,f.num,f.den);
    else
        printf("%d", f.nat);
}

void frDesinteger(Fraction *f) {
    if (f->nat == 0) return;
    int sign = (f->nat < 0) ? -1 : 1;
    if (f->nat < 0) 
        f->num = -f->num;
    f->num = f->num + (f->nat * f->den);
    f->nat = 0;
}

void frMultiply(Fraction f1, Fraction f2, Fraction *result) {
    frDesinteger(&f1);
    frDesinteger(&f2);
    result->num = f1.num * f2.num;
    result->den = f1.den * f2.den;
}

int main(int argc, const char* argv[]){
    Fraction f1, f2, result;
    // f1 = -1 | 1 /5
    f1.nat = -1;
    f1.num = 1;
    f1.den = 5;
    // f2 = 1 | 1 /5
    f2.nat = 1;
    f2.num = 1;
    f2.den = 5;
    // result = 0
    result.nat = 0;
    result.num = 0;
    result.den = 0;

    printf("Before:\n");
    printf("    f1: "); frPrint(f1); printf("\n");
    printf("    f2: "); frPrint(f2); printf("\n");
    printf("result: "); frPrint(result); printf("\n");
    puts("After:");
    frMultiply(f1, f2, &result);
    printf("result: "); frPrint(result); printf("\n");
}