public static bool IsBinarySearchTree(MyTreeNode <T> root)
{
if (root == null)
{
return(false);
}
if (root.LNode == null && root.RNode == null)
{
return(true);
}
if (root.LNode != null && root.RNode != null)
{
if (root.Value.CompareTo(root.LNode.Value) >= 0 && root.Value.CompareTo(root.RNode.Value) <= 0)
{
return(IsBinarySearchTree(root.LNode) && IsBinarySearchTree(root.RNode));
}
return(false);
}
if (root.LNode != null)
{
if (root.Value.CompareTo(root.LNode.Value) < 0)
{
return(false);
}
return(IsBinarySearchTree(root.LNode));
}
if (root.RNode != null)
{
if (root.Value.CompareTo(root.RNode.Value) > 0)
{
return(false);
}
return(IsBinarySearchTree(root.RNode));
}
}
public static MyTreeNode <T> CreateNormalTree(List <T> elements)
{
if (elements.Count == 0)
{
return(null);
}
int elementCount = elements.Count;
int stopIndex = (elementCount + 1) / 2;
MyTreeNode <T>[] listNodes = new MyTreeNode <T> [elementCount];
listNodes[0] = new MyTreeNode <T>(elements[0]);
for (int i = 0; i < stopIndex; i++)
{
MyTreeNode <T> node = listNodes[i];
int lIndex = 2 * i + 1;
if (lIndex < elementCount)
{
MyTreeNode <T> lNode = new MyTreeNode <T>(elements[lIndex]);
node.LNode = lNode;
listNodes[lIndex] = lNode;
}
int rIndex = 2 * (i + 1);
if (rIndex < elementCount)
{
MyTreeNode <T> rNode = new MyTreeNode <T>(elements[rIndex]);
node.RNode = rNode;
listNodes[rIndex] = rNode;
}
}
return(listNodes[0]);
}
static void Main(string[] args)
{
List <int> elements = new List <int>()
{
66, 44, 22, 88, 55, 99, 77, 11, 33, 48
};
MyTreeNode <int> root = NodeController <int> .CrateBinarySearchTree(elements);
List <string> strElements = new List <string>()
{
"Foo", "Afc", "Beyond", "Tarmar", "Coug", "Jerk", "Hour", "Ade"
};
MyTreeNode <string> strRoot = NodeController <string> .CrateBinarySearchTree(strElements);
List <int> norElements = new List <int>()
{
66, 44, 88, 22, 55, 77, 99, 11, 33, 48, 56
};
MyTreeNode <int> norRoot = NodeController <int> .CreateNormalTree(norElements);
bool ret = NodeController <int> .IsBinarySearchTree(root);
bool norRet = NodeController <int> .IsBinarySearchTree(norRoot);
root.LNode.RNode.Value = 45;
ret = NodeController <int> .IsBinarySearchTree(root);
}
public static MyTreeNode <T> CrateBinarySearchTree(List <T> elements)
{
if (elements.Count == 0)
{
return(null);
}
MyTreeNode <T> root = new MyTreeNode <T>(elements[0]);
for (int i = 1; i < elements.Count; i++)
{
InsertNode(root, elements[i]);
}
return(root);
}
private static bool InsertNode(MyTreeNode <T> curNode, T element)
{
if (curNode.Value.CompareTo(element) > 0)
{
if (curNode.LNode == null)
{
curNode.LNode = new MyTreeNode <T>(element);
return(true);
}
return(InsertNode(curNode.LNode, element));
}
else
{
if (curNode.RNode == null)
{
curNode.RNode = new MyTreeNode <T>(element);
return(true);
}
return(InsertNode(curNode.RNode, element));
}
}
public MyTreeNode(T element)
{
Value = element;
LNode = null;
RNode = null;
}