Problem
Repeatedly divide n by 2, dropping any remainder (integer division), until it becomes 1. Count how many divisions that takes.
Implement halve_until_one(n).
Input
n: A positive integer.
Output
Return the number of divisions.
Constraints
1 ≤ n ≤ 1,000,000,000,000
Examples
Example 1
Input:
n = 20
Expected output:
expected = 4Input:
long long n = 20;
Expected output:
long long expected = 4;Input:
long n = 20;
Expected output:
long expected = 4;Explanation
20 → 10 → 5 → 2 → 1 takes 4 divisions.
Example 2
Input:
n = 1
Expected output:
expected = 0Input:
long long n = 1;
Expected output:
long long expected = 0;Input:
long n = 1;
Expected output:
long expected = 0;Explanation
n is already 1, so no divisions are needed.
References
This challenge is adapted for CodeUtility. Follow the statement and constraints above.