Lowest Common Ancestor of Deepest Leaves

Given the root of a binary tree, return the lowest common ancestor of its deepest leaves.

Recall that:

  • The node of a binary tree is a leaf if and only if it has no children.
  • The depth of the root of the tree is 0; if the depth of a node is d, the depth of each of its children is d + 1.
  • The lowest common ancestor of a set S of nodes is the node A with the largest depth such that every node in S is in the subtree with root A.

Note: This question is the same as 865: https://leetcode.com/problems/smallest-subtree-with-all-the-deepest-nodes/

Example 1
        3
       / \
      5   1
     / \ / \
    6  2 0  8
      / \
     7   4
Inputroot = [3,5,1,6,2,0,8,null,null,7,4]
Output[2,7,4]
The node with value 2 is the lowest common ancestor of the deepest leaf nodes 7 and 4.
Example 2
        1
Inputroot = [1]
Output[1]
The root is the deepest node in the tree, and it is the LCA of itself.

Constraints

  • The number of nodes in the tree will be in the range [1, 1000].
  • 0 <= Node.val <= 1000
  • The values of the nodes in the tree are unique.

Asked at 4 companies

</>

Your Solution

(Ctrl/Cmd + Enter)

Switching Language

Loading template...

Loading...

Sign in to save your progress

AI code evaluation

Get a correctness verdict, missed edge cases, and complexity analysis of your solution.

Sign in to evaluate