public/tests/go/func/correct/collatzcountdown.go

package correct

func CollatzCountdown(start int) int {
	if start <= 0 {
		return -1
	}

	steps := 0

	for start != 1 {
		if start%2 == 0 {
			start = start / 2
		} else {
			start = 3*start + 1
		}
		steps++
	}

	return steps
}