<p>Given an integer <code>numRows</code>, return the first numRows of <strong>Pascal's triangle</strong>.</p> <p>In <strong>Pascal's triangle</strong>, each number is the sum of the two numbers directly above it as shown:</p> <img alt="" src="https://upload.wikimedia.org/wikipedia/commons/0/0d/PascalTriangleAnimated2.gif" style="height:240px; width:260px" /> <p> </p> <p><strong class="example">Example 1:</strong></p> <pre><strong>Input:</strong> numRows = 5 <strong>Output:</strong> [[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1]] </pre><p><strong class="example">Example 2:</strong></p> <pre><strong>Input:</strong> numRows = 1 <strong>Output:</strong> [[1]] </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= numRows <= 30</code></li> </ul>