Binary Tree

How to find the depth of a binary tree

 struct Node {   Node(int value)   {     _value = value;     _left = NULL;     _right = NULL;   }    Node* _left;   int _value;   Node* _right; };  int MaxDepth(const Node* root) {   if(root == NULL)     return 0;    int iLeftDepth = MaxDepth(root->_left);   int iRightDepth = MaxDepth(root->_right);    return (iLeftDepth > iRightDepth)          ? (iLeftDepth + 1)          : (iRightDepth + 1); }