N-th

Write a function that takes 2 arguments: a binary tree and an integer n, it should return the n-th element in the inorder traversal of the binary tree.

int findNthElementByInorder(Node *node, int &n)
{
    if (node == null)
        return -1;
    findNthElementByInorder(node->left, n);
    if (n == 0)
        return node-> value;
    else
       n--;
   findNthElementByInorder(node->right, n);
}