How to find min or max value in a given binary tree

This is a continuation of my post How to create a binary tree in c#.In this post, I will show you how to find max or min value in a given binary tree.

Min Value: Loop down to find the leftmost leaf

Max Value: Loop down to find the rightmost leaf

public int FindMinValue()
        {
            return FindMinValue(_root);
        }

        private int FindMinValue(Node root)
        {
            if (root == null)
                return -1;
            else
            {
                Node current = root;
                while (current.Left!=null)
                {
                    current = current.Left;
                }
                return current.Data;

            }
        }
        public int FindMaxValue()
        {
            return FindMaxValue(_root);

        }

        private int FindMaxValue(Node root)
        {
            if (_root == null)
                return -1;
            else
            {
                Node current = root;
                while (current.Right!=null)
                {
                    current = current.Right;
                }
                return current.Data;
            }
        }