func rotLeft(a []int32, d int32) []int32 {
	size := int32(len(a))
	d = d % size
	if d == 0 {
		return a
	}

	m, n, r := 0, d, d
	for i := int32(1); i <= d && n < size; i++ {
		x := a[m]
		a[m] = a[n]
		a[n] = x

		m++
		n++
		r--
	}

	if n == size {
		rotLeft(a[m:], r)
	} else {
		rotLeft(a[d:], d)
	}

	return a
}