https://dmytros.blog/tags/valid-parenthesis-string/ Recent content in Valid Parenthesis String on Dmytro's Blog https://dmytros.blog/images/papermod-cover.png https://dmytros.blog/images/papermod-cover.png Hugo en Tue, 26 May 2026 08:05:31 +0300 https://dmytros.blog/posts/leetcode-150-valid-parenthesis-string/ Tue, 26 May 2026 08:05:31 +0300 https://dmytros.blog/posts/leetcode-150-valid-parenthesis-string/ <h3 id="the-problem">The problem</h3> <p>Given a string <code>s</code> containing only three types of characters: <code>'('</code>, <code>')'</code>, and <code>'*'</code>, return <code>true</code> <em>if</em> <code>s</code> <em>is <strong>valid</strong></em>.</p> <p>The following rules define a <strong>valid</strong> string:</p> <ul> <li>Any left parenthesis <code>'('</code> must have a corresponding right parenthesis <code>')'</code>.</li> <li>Any right parenthesis <code>')'</code> must have a corresponding left parenthesis <code>'('</code>.</li> <li>A left parenthesis <code>'('</code> must go before the corresponding right parenthesis <code>')'</code>.</li> <li><code>'*'</code> could be treated as a single right parenthesis <code>')'</code>, a single left parenthesis <code>'('</code>, or an empty string <code>&quot;&quot;</code>.</li> </ul> <p><strong>Example 1:</strong></p>