static void Main(string[] args)
{
Program binaryTree = new Program();
Node rootNode = binaryTree.InsertNode(null, 2);
binaryTree.InsertNode(rootNode, 5);
binaryTree.InsertNode(rootNode, 34);
binaryTree.InsertNode(rootNode, 22);
binaryTree.InsertNode(rootNode, 6);
binaryTree.InsertNode(rootNode, 45);
binaryTree.InsertNode(rootNode, 3);
binaryTree.InsertNode(rootNode, 3);
binaryTree.InsertNode(rootNode, 76);
binaryTree.InsertNode(rootNode, 5);
binaryTree.InsertNode(rootNode, 4);
binaryTree.InsertNode(rootNode, 8);
int searchValue = 45;
Node foundNode = binaryTree.FindNode(rootNode, searchValue);
if (foundNode != null)
{
Console.WriteLine("Found Node {0} with value {1}", foundNode, foundNode.GetValue());
}
else
{
Console.WriteLine("No node found with value {0}", searchValue);
}
}
/// <summary>
/// Returns a Node object with the specified value, or null if no node exists in the tree with the
/// value specified. This is a recursive method. You should only call this method using the root node.
/// </summary>
/// <param name="rootNode">The current location in the tree. You should only call this method with the root node</param>
/// <param name="searchValue">The value we are searching for</param>
/// <returns></returns>
public Node FindNode(Node rootNode, int searchValue)
{
if (rootNode == null) //we have reached the end of the tree, and the search value was never found
{
return(null);
}
else if (searchValue == rootNode.GetValue()) //we have found the node we were looking for, so return it
{
return(rootNode);
}
else if (searchValue < rootNode.GetValue()) // The current node's value is greater than the search value, so look to the left
{
return(FindNode(rootNode.leftNode, searchValue));
}
else
{
return(FindNode(rootNode.rightNode, searchValue)); // The current node's value is less than the search value, so look to the right
}
}
/// <summary>
/// Recursively inserts a node into the correct location in the binary search tree. Call this method with the root node of the tree
/// </summary>
/// <param name="rootNode">The current location in the tree. You should only ever call this with the root node</param>
/// <param name="value">The value of the new node</param>
/// <returns></returns>
public Node InsertNode(Node rootNode, int value)
{
if (rootNode == null) //we have reached the end of the tree, so insert the new node here
{
Node newNode = new Node(value);
rootNode = newNode;
}
else if (value > rootNode.GetValue()) // The current node's value is smaller than the new node's value, so insert to the right
{
rootNode.rightNode = InsertNode(rootNode.rightNode, value);
}
else
{
rootNode.leftNode = InsertNode(rootNode.leftNode, value); // The current node's value is greater than the new node's value, so insert to the left
}
return(rootNode);
}
//후위순회 왼-오-중
public void PostorderTraversal(Node currentNode)
{
if (rootNode == null)
{
Console.WriteLine("빈 트리 입니다.");
return;
}
if (currentNode.GetLeft() != null)
{
PostorderTraversal(currentNode.GetLeft());
}
if (currentNode.GetRight() != null)
{
PostorderTraversal(currentNode.GetRight());
}
Console.Write($"{currentNode.GetValue()} ");
}