g0501_0600.s0501_find_mode_in_binary_search_tree

Class Solution

java.lang.Object

g0501_0600.s0501_find_mode_in_binary_search_tree.Solution

public class Solution
extends Object

501 - Find Mode in Binary Search Tree.

Easy

Given the root of a binary search tree (BST) with duplicates, return all the [mode(s)](https://en.wikipedia.org/wiki/Mode_(statistics)) (i.e., the most frequently occurred element) in it.

If the tree has more than one mode, return them in any order.

Assume a BST is defined as follows:

• The left subtree of a node contains only nodes with keys less than or equal to the node’s key.
• The right subtree of a node contains only nodes with keys greater than or equal to the node’s key.
• Both the left and right subtrees must also be binary search trees.

Example 1:

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

Output: [2]

Example 2:

Input: root = [0]

Output: [0]

Constraints:

• The number of nodes in the tree is in the range [1, 104].
• -105 <= Node.val <= 105

Follow up: Could you do that without using any extra space? (Assume that the implicit stack space incurred due to recursion does not count).

Constructor Summary

Constructors

Constructor and Description
Solution()

Method Summary

Modifier and Type	Method and Description
int[]	findMode(TreeNode root)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

findMode

public int[] findMode(TreeNode root)