/**

* Definition for a binary tree node.

* public class TreeNode {

* int val;

* TreeNode left;

* TreeNode right;

* TreeNode() {}

* TreeNode(int val) { this.val = val; }

* TreeNode(int val, TreeNode left, TreeNode right) {

* this.val = val;

* this.left = left;

* this.right = right;

* }

* }

*/

class Solution {

HashMap<Integer,Integer> map = new HashMap<>();

public int[] findMode(TreeNode root) {

if(root == null){

return new int[0];

}

inOrderTraversal(root);

List<Integer> list = new ArrayList<>();

int maxCount = Collections.max(map.values());

for (Map.Entry<Integer, Integer> entry : map.entrySet()) {

if (entry.getValue() == maxCount) {

list.add(entry.getKey());

}

}

int[] result = new int[list.size()];

for (int i = 0; i < list.size(); i++) {

result[i] = list.get(i);

}

return result;

}

public void inOrderTraversal(TreeNode root) {

if (root != null) {

inOrderTraversal(root.left);

map.put(root.val, map.getOrDefault(root.val, 0) + 1);

inOrderTraversal(root.right);

}

}

}