Binary Number with Alternating Bits

Problem

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.

Solution

Bit Manipulation Solution

public class Solution {
    public boolean hasAlternatingBits(int n) {
        int diff = n & 1;
        n = n >> 1;
        while (n != 0) {
            int temp = n & 1;
            if (diff == temp) return false;
            diff = temp;
            n = n >> 1;
        }
        return true;
    }
}

Analysis

An easy bit manipulation problem
We just need to right shit n and check if the result of n & 1 changed every time