#include <stdio.h>

typedef struct frac{
    int n;
    int d;
} frac;

frac soma(frac a, frac b);
frac subtrai(frac a, frac b);
frac multiplica(frac a, frac b);
frac divide(frac a, frac b);

int main()
{
    frac a = {1,2}, b = {2,1}, c;
    c = soma(a, b);
    printf("1/2 + 2 = %d/%d\n", c.n, c.d);
    c = subtrai(a, b);
    printf("1/2 - 2 = %d/%d\n", c.n, c.d);
    c = multiplica(a, b);
    printf("1/2 * 2 = %d/%d\n", c.n, c.d);
    c = divide(a, b);
    printf("1/2 / 2 = %d/%d\n", c.n, c.d);
    system("pause");
    return 0;
}

frac soma(frac a, frac b)
{
     frac c;
     c.n = a.n * b.d + b.n * a.d;
     c.d = a.d * b.d;
     return c;
}

frac subtrai(frac a, frac b)
{
     frac c;
     c.n = a.n * b.d - b.n * a.d;
     c.d = a.d * b.d;
     return c;
}

frac multiplica(frac a, frac b)
{
     frac c;
     c.n = a.n * b.n;
     c.d = a.d * b.d;
     return c;
}

frac divide(frac a, frac b)
{
     frac c;
     c.n = a.n * b.d;
     c.d = a.d * b.n;
     return c;
}