如何在C++中查找二叉树中的最接近或精确的值

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

void findClosestValue(TreeNode* node, double target, int& closestValue) {
    if (node == nullptr) {
        return;
    }
    
    if (abs(node->val - target) < abs(closestValue - target)) {
        closestValue = node->val;
    }
    
    if (target < node->val) {
        findClosestValue(node->left, target, closestValue);
    } else {
        findClosestValue(node->right, target, closestValue);
    }
}

int findClosestValueInBST(TreeNode* root, double target) {
    int closestValue = root->val;
    findClosestValue(root, target, closestValue);
    return closestValue;
}