https://leetcode.com/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one/

https://leetcode.com/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one/discuss/564287/C%2B%2BJava-O(n)

Given a number s in their binary representation. Return the number of steps to reduce it to 1 under the following rules:

If the current number is even, you have to divide it by 2.

If the current number is odd, you have to add 1 to it.

It’s guaranteed that you can always reach to one for all testcases.

Example 1:

Input: s = “1101”

Output: 6

Explanation: “1101” corressponds to number 13 in their decimal representation.

Step 1) 13 is odd, add 1 and obtain 14.

Step 2) 14 is even, divide by 2 and obtain 7.

Step 3) 7 is odd, add 1 and obtain 8.

Step 4) 8 is even, divide by 2 and obtain 4.

Step 5) 4 is even, divide by 2 and obtain 2.

Step 6) 2 is even, divide by 2 and obtain 1.

Example 2:

Input: s = “10”

Output: 1

Explanation: “10” corressponds to number 2 in their decimal representation.

Step 1) 2 is even, divide by 2 and obtain 1.

Example 3:

Input: s = “1”

Output: 0

Constraints:

1 <= s.length <= 500

s consists of characters ‘0’ or ‘1’

s[0] == ‘1’

1 | class Solution { |