I spent about 10 hours and got AC.
I write long racional arithmetic.
Please, send me prog with int64 only (efrcom [at] yandex [dot] ru)

Edited by author 28.10.2006 22:51

Just reduce as much as possoble before actual operation:

tf operator + (const tf& f1, const tf& f2)
{
    int64 d  = gcd(f1.b, f2.b);
    int64 m1 = f2.b/d;
    int64 m2 = f1.b/d;
    return tf(f1.a*m1 + f2.a*m2, f1.b*m1);
}

tf operator - (const tf& f1, const tf& f2)
{
    int64 d  = gcd(f1.b, f2.b);
    int64 m1 = f2.b/d;
    int64 m2 = f1.b/d;
    return tf(f1.a*m1 - f2.a*m2, f1.b*m1);
}

tf operator * (const tf& f1, const tf& f2)
{
    int64 d1 = gcd(f1.a, f2.b);
    int64 d2 = gcd(f2.a, f1.b);
    return tf((f1.a/d1)*(f2.a/d2), (f1.b/d2)*(f2.b/d1));
}

tf operator / (const tf& f1, const tf& f2)
{
    assert(f2.a);
    return f1*tf(f2.b, f2.a);
}

fractions are further reduced inside 'tf(int64, int64)' constructor.

Edited by author 12.08.2008 05:28