Find the Difference
<p>You are given two strings <code>s</code> and <code>t</code>.</p>

<p>String <code>t</code> is generated by random shuffling string <code>s</code> and then add one more letter at a random position.</p>

<p>Return the letter that was added to <code>t</code>.</p>

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

<pre>
<strong>Input:</strong> s = &quot;abcd&quot;, t = &quot;abcde&quot;
<strong>Output:</strong> &quot;e&quot;
<strong>Explanation:</strong> &#39;e&#39; is the letter that was added.
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;&quot;, t = &quot;y&quot;
<strong>Output:</strong> &quot;y&quot;
</pre>

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

<ul>
	<li><code>0 &lt;= s.length &lt;= 1000</code></li>
	<li><code>t.length == s.length + 1</code></li>
	<li><code>s</code> and <code>t</code> consist of lowercase English letters.</li>
</ul>
Bit Manipulation; Hash Table; String; Sorting
class Solution {
    public char findTheDifference(String s, String t) {
        int[] cnt = new int[26];
        for (int i = 0; i < s.length(); ++i) {
            ++cnt[s.charAt(i) - 'a'];
        }
        for (int i = 0;; ++i) {
            if (--cnt[t.charAt(i) - 'a'] < 0) {
                return t.charAt(i);
            }
        }
    }
}