codewars/go/kyu7/a_rule_of_divisibility_by_7/k.go

package kata

func Seven(n int64) []int {
	steps := 0
	current := int(n)
	for {
		n1, n2 := current / 10, current % 10
		if current < 100 {
			break
		}
		current = n1 - 2*n2
		steps++
	}

	return []int{current, steps}
}