[algorithm] Finding height in Binary Search Tree

//function to find height of BST

int height(Node* root) {
    if(root == NULL){
        return -1;
    }

    int sum=0;
    int rheight = height(root->right);
    int lheight = height(root->left);

    if(lheight>rheight){
        sum = lheight +1;
    }
    if(rheight > lheight){
        sum = rheight + 1;
    }

    return sum;
}