<p>You have <code>n</code> coins and you want to build a staircase with these coins. The staircase consists of <code>k</code> rows where the <code>i<sup>th</sup></code> row has exactly <code>i</code> coins. The last row of the staircase <strong>may be</strong> incomplete.</p> <p>Given the integer <code>n</code>, return <em>the number of <strong>complete rows</strong> of the staircase you will build</em>.</p> <p> </p> <p><strong>Example 1:</strong></p> <img alt="" src="https://assets.leetcode.com/uploads/2021/04/09/arrangecoins1-grid.jpg" style="width: 253px; height: 253px;" /> <pre> <strong>Input:</strong> n = 5 <strong>Output:</strong> 2 <strong>Explanation:</strong> Because the 3<sup>rd</sup> row is incomplete, we return 2. </pre> <p><strong>Example 2:</strong></p> <img alt="" src="https://assets.leetcode.com/uploads/2021/04/09/arrangecoins2-grid.jpg" style="width: 333px; height: 333px;" /> <pre> <strong>Input:</strong> n = 8 <strong>Output:</strong> 3 <strong>Explanation:</strong> Because the 4<sup>th</sup> row is incomplete, we return 3. </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= n <= 2<sup>31</sup> - 1</code></li> </ul>