static bool isBinaryTree(NodeTree root)
{
// traverse the tree in inorder fashion and
// keep track of prev node
if (root != null)
{
if (!isBinaryTree(root.Left))
{
return(false);
}
// Allows only distinct valued nodes
if (prev != null &&
root.Data <= prev.Data)
{
return(false);
}
prev = root;
return(isBinaryTree(root.Right));
}
return(true);
}
static NodeTree Insert(NodeTree root, int data)
{
if (root == null)
{
return(new NodeTree(data));
}
else
{
NodeTree cur;
if (data <= root.Data)
{
cur = Insert(root.Left, data);
root.Left = cur;
}
else
{
cur = Insert(root.Right, data);
root.Right = cur;
}
return(root);
}
}
static bool CheckBinaryTree(NodeTree root)
{
return(isBinaryTree(root));
}
public NodeTree(int data)
{
this.Data = data;
Left = Right = null;
}