human
What is a the minimum number of replacements needed for n to become 1 given the following:
Solve in Python:
Given a positive integer n and you can do operations as follow:



If n is even, replace n with n/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
assistant
#Here is the minimum number of replacements needed for n to become 1.

class Solution:
     def integerReplacement(self, n):
         """
         :type n: int
         :rtype: int
         """
         def dfs(n):
             if n==1: return 0
             if n==3: return 2
             if (n & 0x1)==0: return dfs(n>>1)+1
             elif ((n>>1) & 0x1)==0: return dfs(n-1)+1
             else: return dfs(n+1)+1
             
         return dfs(n)