Halving Steps in Scala

Given a positive integer n, return how many times you have to divide it by 2 until it becomes 1.

Every division is an integer division: the remainder is dropped, so 9 divided by 2 gives 4. Keep dividing the new value by 2 until it is 1, and count the divisions. If n is already 1, no division is needed.

Example 1:

Input: n = 8
Output: 3
Explanation: 8 → 4 → 2 → 1: three divisions by 2.

Example 2:

Input: n = 9
Output: 3
Explanation: 9 → 4 → 2 → 1. 9 divided by 2 gives 4, because the remainder 1 is dropped.

Example 3:

Input: n = 1
Output: 0
Explanation: n is already 1, so there is nothing to divide.

Constraints:

• 1 <= n <= 109