Rounding to nearest

RoundToNearest.cpp

// round n down to nearest multiple of m
int roundDown (int n, int m) 
{
    return n >= 0 ? (n / m) * m : ((n - m + 1) / m) * m;
}

// round n up to nearest multiple of m
int roundUp (int n, int m) 
{
    return n >= 0 ? ((n + m - 1) / m) * m : (n / m) * m;
}