397 - Integer Replacement
Written on November 12, 2017
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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?
class Solution(object):
def integerReplacement(self, n):
"""
:type n: int
:rtype: int
"""
count = 0
while n > 1:
if n % 2 == 0:
n /= 2
else:
if (n + 1) % 4 == 0 and n != 3:
n += 1
else:
n -= 1
count += 1
return count