0397. Integer Replacement

397. Integer Replacement

Topics

• Math
• Bit Manipulation

Given a positive integer n and you can do operations as follow:

1. If n is even, replace n with n/2.
2. If n is odd, you can replace n with either n + 1 or n - 1.

What is the minimum number of replacements needed for n to become 1?

Example 1:

Input:

8

Output:

3

Explanation:

8 -> 4 -> 2 -> 1

Example 2:

Input:

7

Output:

4

Explanation:

7 -> 8 -> 4 -> 2 -> 1

or

7 -> 6 -> 3 -> 2 -> 1