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            "title": "Longest Duplicate Substring",
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            "content": "<p>Given a string <code>s</code>, consider all <em>duplicated substrings</em>: (contiguous) substrings of s that occur 2 or more times.&nbsp;The occurrences&nbsp;may overlap.</p>\n\n<p>Return <strong>any</strong> duplicated&nbsp;substring that has the longest possible length.&nbsp;If <code>s</code> does not have a duplicated substring, the answer is <code>&quot;&quot;</code>.</p>\n\n<p>&nbsp;</p>\n<p><strong>Example 1:</strong></p>\n<pre><strong>Input:</strong> s = \"banana\"\n<strong>Output:</strong> \"ana\"\n</pre><p><strong>Example 2:</strong></p>\n<pre><strong>Input:</strong> s = \"abcd\"\n<strong>Output:</strong> \"\"\n</pre>\n<p>&nbsp;</p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>2 &lt;= s.length &lt;= 3 * 10<sup>4</sup></code></li>\n\t<li><code>s</code> consists of lowercase English letters.</li>\n</ul>\n",
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                "Binary search for the length of the answer.  (If there's an answer of length 10, then there are answers of length 9, 8, 7, ...)",
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