1457

/**
 * 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:
    int ans = 0, bit = 0;
    int pseudoPalindromicPaths (TreeNode* root) {
        dfs(root);
        return ans;
    }

    void dfs(TreeNode* node){
        if(!node) return;
        bit ^= (1 << (node->val));
        dfs(node->left);
        dfs(node->right);
        if(!node->left && !node->right && !(bit & bit-1))
            ans++;
        bit ^= (1 << (node->val));
    }
};