<p>Given two strings <code>word1</code> and <code>word2</code>, return <em>the minimum number of operations required to convert <code>word1</code> to <code>word2</code></em>.</p> <p>You have the following three operations permitted on a word:</p> <ul> <li>Insert a character</li> <li>Delete a character</li> <li>Replace a character</li> </ul> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> word1 = "horse", word2 = "ros" <strong>Output:</strong> 3 <strong>Explanation:</strong> horse -> rorse (replace 'h' with 'r') rorse -> rose (remove 'r') rose -> ros (remove 'e') </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> word1 = "intention", word2 = "execution" <strong>Output:</strong> 5 <strong>Explanation:</strong> intention -> inention (remove 't') inention -> enention (replace 'i' with 'e') enention -> exention (replace 'n' with 'x') exention -> exection (replace 'n' with 'c') exection -> execution (insert 'u') </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 <= word1.length, word2.length <= 500</code></li> <li><code>word1</code> and <code>word2</code> consist of lowercase English letters.</li> </ul>