java.lang.Object
g1301_1400.s1373_maximum_sum_bst_in_binary_tree.Solution

public class Solution extends Object
1373 - Maximum Sum BST in Binary Tree.<p>Hard</p> <p>Given a <strong>binary tree</strong> <code>root</code>, return <em>the maximum sum of all keys of <strong>any</strong> sub-tree which is also a Binary Search Tree (BST)</em>.</p> <p>Assume a BST is defined as follows:</p> <ul> <li>The left subtree of a node contains only nodes with keys <strong>less than</strong> the node&rsquo;s key.</li> <li>The right subtree of a node contains only nodes with keys <strong>greater than</strong> the node&rsquo;s key.</li> <li>Both the left and right subtrees must also be binary search trees.</li> </ul> <p><strong>Example 1:</strong></p> <p><img src="https://assets.leetcode.com/uploads/2020/01/30/sample_1_1709.png" alt="" /></p> <p><strong>Input:</strong> root = [1,4,3,2,4,2,5,null,null,null,null,null,null,4,6]</p> <p><strong>Output:</strong> 20</p> <p><strong>Explanation:</strong> Maximum sum in a valid Binary search tree is obtained in root node with key equal to 3.</p> <p><strong>Example 2:</strong></p> <p><img src="https://assets.leetcode.com/uploads/2020/01/30/sample_2_1709.png" alt="" /></p> <p><strong>Input:</strong> root = [4,3,null,1,2]</p> <p><strong>Output:</strong> 2</p> <p><strong>Explanation:</strong> Maximum sum in a valid Binary search tree is obtained in a single root node with key equal to 2.</p> <p><strong>Example 3:</strong></p> <p><strong>Input:</strong> root = [-4,-2,-5]</p> <p><strong>Output:</strong> 0</p> <p><strong>Explanation:</strong> All values are negatives. Return an empty BST.</p> <p><strong>Constraints:</strong></p> <ul> <li>The number of nodes in the tree is in the range <code>[1, 4 * 10<sup>4</sup>]</code>.</li> <li><code>-4 * 10<sup>4</sup> <= Node.val <= 4 * 10<sup>4</sup></code></li> </ul>
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • maxSumBST

      public int maxSumBST(TreeNode root)