<p>Given the <code>root</code> of a binary tree, return the most frequent <strong>subtree sum</strong>. If there is a tie, return all the values with the highest frequency in any order.</p>

<p>The <strong>subtree sum</strong> of a node is defined as the sum of all the node values formed by the subtree rooted at that node (including the node itself).</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/04/24/freq1-tree.jpg" style="width: 207px; height: 183px;" />
<pre>
<strong>Input:</strong> root = [5,2,-3]
<strong>Output:</strong> [2,-3,4]
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/04/24/freq2-tree.jpg" style="width: 207px; height: 183px;" />
<pre>
<strong>Input:</strong> root = [5,2,-5]
<strong>Output:</strong> [2]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li>The number of nodes in the tree is in the range <code>[1, 10<sup>4</sup>]</code>.</li>
	<li><code>-10<sup>5</sup> &lt;= Node.val &lt;= 10<sup>5</sup></code></li>
</ul>

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
    vector<int> findMaxFrequency(const vector<int>& nums) {
    unordered_map<int, int> freqMap;
    int maxFreq = 0;
    vector<int> mostFrequentNums;

    for (int num : nums) {
        freqMap[num]++;
        if (freqMap[num] > maxFreq) {
            maxFreq = freqMap[num];
        }
    }

    for (const auto& entry : freqMap) {
        if (entry.second == maxFreq) {
            mostFrequentNums.push_back(entry.first);
        }
    }

    return mostFrequentNums;
}
    int sum(TreeNode *root){
        if(root==nullptr)
            return 0;
        return root->val+sum(root->left)+sum(root->right);
    }
    void help(TreeNode *root,vector<int>&a){
        if(root==nullptr)
            return;
        a.push_back(sum(root));
        help(root->left,a);
        help(root->right,a);
    }
    vector<int> findFrequentTreeSum(TreeNode* root) {
        vector<int>ans;
        help(root,ans);
        return findMaxFrequency(ans);
    }
};
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