Binary Number with Alternating Bits
<p>Given a positive integer, check whether it has alternating bits: namely, if two adjacent bits will always have different values.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> n = 5
<strong>Output:</strong> true
<strong>Explanation:</strong> The binary representation of 5 is: 101
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> n = 7
<strong>Output:</strong> false
<strong>Explanation:</strong> The binary representation of 7 is: 111.</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> n = 11
<strong>Output:</strong> false
<strong>Explanation:</strong> The binary representation of 11 is: 1011.</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= n &lt;= 2<sup>31</sup> - 1</code></li>
</ul>
Bit Manipulation
class Solution {
    public boolean hasAlternatingBits(int n) {
        int prev = -1;
        while (n != 0) {
            int curr = n & 1;
            if (prev == curr) {
                return false;
            }
            prev = curr;
            n >>= 1;
        }
        return true;
    }
}