<p>You are given an array of strings <code>words</code> and a string <code>pref</code>.</p> <p>Return <em>the number of strings in </em><code>words</code><em> that contain </em><code>pref</code><em> as a <strong>prefix</strong></em>.</p> <p>A <strong>prefix</strong> of a string <code>s</code> is any leading contiguous substring of <code>s</code>.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> words = ["pay","<strong><u>at</u></strong>tention","practice","<u><strong>at</strong></u>tend"], <code>pref </code>= "at" <strong>Output:</strong> 2 <strong>Explanation:</strong> The 2 strings that contain "at" as a prefix are: "<u><strong>at</strong></u>tention" and "<u><strong>at</strong></u>tend". </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> words = ["leetcode","win","loops","success"], <code>pref </code>= "code" <strong>Output:</strong> 0 <strong>Explanation:</strong> There are no strings that contain "code" as a prefix. </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= words.length <= 100</code></li> <li><code>1 <= words[i].length, pref.length <= 100</code></li> <li><code>words[i]</code> and <code>pref</code> consist of lowercase English letters.</li> </ul>