public void TestFirstCase()
{
var root = new TreeNode(3, new TreeNode(9), new TreeNode(20, new TreeNode(15), new TreeNode(7)));
var maxDepth = new MaxDepth(root);
var result = maxDepth.GetMaxDepth();
Assert.AreEqual(3, result);
}
public int MaxDepth(TreeNode root)
{
var maxDepth = new MaxDepth(root);
return(maxDepth.GetMaxDepth());
}