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

Example 1:

    Input: n = 5
    Output: true
    Explanation: The binary representation of 5 is: 101

Example 2:

    Input: n = 7
    Output: false
    Explanation: The binary representation of 7 is: 111.

Example 3:

    Input: n = 11
    Output: false
    Explanation: The binary representation of 11 is: 1011.

Constraints:

- `1 <= n <= 231 - 1`