<p>Given an array of integers <code>arr</code>, return <code>true</code> if we can partition the array into three <strong>non-empty</strong> parts with equal sums.</p> <p>Formally, we can partition the array if we can find indexes <code>i + 1 < j</code> with <code>(arr[0] + arr[1] + ... + arr[i] == arr[i + 1] + arr[i + 2] + ... + arr[j - 1] == arr[j] + arr[j + 1] + ... + arr[arr.length - 1])</code></p> <p> </p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> arr = [0,2,1,-6,6,-7,9,1,2,0,1] <strong>Output:</strong> true <strong>Explanation: </strong>0 + 2 + 1 = -6 + 6 - 7 + 9 + 1 = 2 + 0 + 1 </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> arr = [0,2,1,-6,6,7,9,-1,2,0,1] <strong>Output:</strong> false </pre> <p><strong class="example">Example 3:</strong></p> <pre> <strong>Input:</strong> arr = [3,3,6,5,-2,2,5,1,-9,4] <strong>Output:</strong> true <strong>Explanation: </strong>3 + 3 = 6 = 5 - 2 + 2 + 5 + 1 - 9 + 4 </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>3 <= arr.length <= 5 * 10<sup>4</sup></code></li> <li><code>-10<sup>4</sup> <= arr[i] <= 10<sup>4</sup></code></li> </ul>