Swap For Longest Repeated Character Substring
<p>You are given a string <code>text</code>. You can swap two of the characters in the <code>text</code>.</p>

<p>Return <em>the length of the longest substring with repeated characters</em>.</p>

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

<pre>
<strong>Input:</strong> text = &quot;ababa&quot;
<strong>Output:</strong> 3
<strong>Explanation:</strong> We can swap the first &#39;b&#39; with the last &#39;a&#39;, or the last &#39;b&#39; with the first &#39;a&#39;. Then, the longest repeated character substring is &quot;aaa&quot; with length 3.
</pre>

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

<pre>
<strong>Input:</strong> text = &quot;aaabaaa&quot;
<strong>Output:</strong> 6
<strong>Explanation:</strong> Swap &#39;b&#39; with the last &#39;a&#39; (or the first &#39;a&#39;), and we get longest repeated character substring &quot;aaaaaa&quot; with length 6.
</pre>

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

<pre>
<strong>Input:</strong> text = &quot;aaaaa&quot;
<strong>Output:</strong> 5
<strong>Explanation:</strong> No need to swap, longest repeated character substring is &quot;aaaaa&quot; with length is 5.
</pre>

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

<ul>
	<li><code>1 &lt;= text.length &lt;= 2 * 10<sup>4</sup></code></li>
	<li><code>text</code> consist of lowercase English characters only.</li>
</ul>
Hash Table; String; Sliding Window
class Solution {
    public int maxRepOpt1(String text) {
        int[] cnt = new int[26];
        int n = text.length();
        for (int i = 0; i < n; ++i) {
            ++cnt[text.charAt(i) - 'a'];
        }
        int ans = 0, i = 0;
        while (i < n) {
            int j = i;
            while (j < n && text.charAt(j) == text.charAt(i)) {
                ++j;
            }
            int l = j - i;
            int k = j + 1;
            while (k < n && text.charAt(k) == text.charAt(i)) {
                ++k;
            }
            int r = k - j - 1;
            ans = Math.max(ans, Math.min(l + r + 1, cnt[text.charAt(i) - 'a']));
            i = j;
        }
        return ans;
    }
}