https://depoze.xyz/tags/leetcode/Recent content in LeetCode on CuSO4_DepositHugozh-CNMon, 28 Sep 2026 00:00:00 +0000https://depoze.xyz/pages/leetcode-142/Wed, 26 Apr 2023 00:00:00 +0000https://depoze.xyz/pages/leetcode-142/<h2 id="problem">Problem</h2> <p>Given the <code>head</code> of a linked list, return <em>the node where the cycle begins. If there is no cycle, return</em> <code>null</code>.</p> <p>There is a cycle in a linked list if there is some node in the list that can be reached again by continuously following the <code>next</code> pointer. Internally, <code>pos</code> is used to denote the index of the node that tail&rsquo;s <code>next</code> pointer is connected to (<strong>0-indexed</strong>). It is <code>-1</code> if there is no cycle. <strong>Note that</strong> <code>pos</code> <strong>is not passed as a parameter</strong>.</p>