Leetcode/693.py at master · ketulsuthar/Leetcode · GitHub

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'''
693. Binary Number with Alternating Bits

Given a positive integer, check whether it has alternating bits: namely, if two adjacent bits will always have different values.

Example 1:
Input: 5
Output: True
Explanation:
The binary representation of 5 is: 101
Example 2:
Input: 7
Output: False
Explanation:
The binary representation of 7 is: 111.
Example 3:
Input: 11
Output: False
Explanation:
The binary representation of 11 is: 1011.
Example 4:
Input: 10
Output: True
Explanation:
The binary representation of 10 is: 1010.

'''

class Solution(object):
    def hasAlternatingBits(self, n):
        """
        :type n: int
        :rtype: bool
        """

        bits= [ int(i) for i in '{0:b}'.format(n) ]
        l = len(bits)
        i = 0
        while l-i > 1:
            if bits[i] - bits[i+1] in [-1,1]:
                i = i + 1
            else:
                return False

        return True