public int Diameter()
{
HeightPath height = new HeightPath();
var diameterRecursive = DiameterRecursive(root, height);
return(diameterRecursive > 0 ? diameterRecursive - 1 : diameterRecursive);
}
private int DiameterRecursive(TreeNode node, HeightPath height)
{
if (node == null)
{
height.Height = 0;
return(0);
}
var leftPathHeight = new HeightPath();
var rightPathHeight = new HeightPath();
int leftDiameter = DiameterRecursive(node.left, leftPathHeight);
int rightDiameter = DiameterRecursive(node.right, rightPathHeight);
height.Height = Math.Max(leftPathHeight.Height, rightPathHeight.Height) + 1;
return(Math.Max(leftPathHeight.Height + rightPathHeight.Height + 1,
Math.Max(leftDiameter, rightDiameter)));
}
