struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x): val(x), left(nullptr), right(nullptr) {}
};

TreeNode* bfsFind(TreeNode* root, int x) {
    if (!root) return nullptr;

    queue<TreeNode*> q;
    q.push(root);

    while (!q.empty()) {
        TreeNode* cur = q.front(); q.pop();
        if (cur->val == x) return cur;
        ________________________
    }
    return nullptr;
}