Package g0801_0900.s0865_smallest_subtree_with_all_the_deepest_nodes

Class Solution

  • public class Solution
extends Object
    865 - Smallest Subtree with all the Deepest Nodes.

    Medium

    Given the root of a binary tree, the depth of each node is the shortest distance to the root.

    Return the smallest subtree such that it contains all the deepest nodes in the original tree.

    A node is called the deepest if it has the largest depth possible among any node in the entire tree.

    The subtree of a node is a tree consisting of that node, plus the set of all descendants of that node.

    Example 1:

    Input: root = [3,5,1,6,2,0,8,null,null,7,4]

    Output: [2,7,4]

    Explanation:

    We return the node with value 2, colored in yellow in the diagram.

    The nodes coloured in blue are the deepest nodes of the tree.

    Notice that nodes 5, 3 and 2 contain the deepest nodes in the tree but node 2 is the smallest subtree among them, so we return it.

    Example 2:

    Input: root = [1]

    Output: [1]

    Explanation: The root is the deepest node in the tree.

    Example 3:

    Input: root = [0,1,3,null,2]

    Output: [2]

    Explanation: The deepest node in the tree is 2, the valid subtrees are the subtrees of nodes 2, 1 and 0 but the subtree of node 2 is the smallest.

    Constraints:

    • The number of nodes in the tree will be in the range [1, 500].
    • 0 <= Node.val <= 500
    • The values of the nodes in the tree are unique.

    Note: This question is the same as 1123: https://leetcode.com/problems/lowest-common-ancestor-of-deepest-leaves/

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • subtreeWithAllDeepest

        public TreeNode subtreeWithAllDeepest​(TreeNode root)