国外版

算法题（国外版）/valid-parentheses.html

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+<p>Given a string <code>s</code> containing just the characters <code>&#39;(&#39;</code>, <code>&#39;)&#39;</code>, <code>&#39;{&#39;</code>, <code>&#39;}&#39;</code>, <code>&#39;[&#39;</code> and <code>&#39;]&#39;</code>, determine if the input string is valid.</p>
+
+<p>An input string is valid if:</p>
+
+<ol>
+	<li>Open brackets must be closed by the same type of brackets.</li>
+	<li>Open brackets must be closed in the correct order.</li>
+</ol>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> s = &quot;()&quot;
+<strong>Output:</strong> true
+</pre>
+
+<p><strong>Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> s = &quot;()[]{}&quot;
+<strong>Output:</strong> true
+</pre>
+
+<p><strong>Example 3:</strong></p>
+
+<pre>
+<strong>Input:</strong> s = &quot;(]&quot;
+<strong>Output:</strong> false
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= s.length &lt;= 10<sup>4</sup></code></li>
+	<li><code>s</code> consists of parentheses only <code>&#39;()[]{}&#39;</code>.</li>
+</ul>