public static BinaryTree ModifyTree(BinaryTree binaryTree)
{
if (binaryTree == null)
{
Console.WriteLine("Input BST is null. There is nothing to modify!");
return(null);
}
Console.WriteLine("Modifying Root Node with the first Node in left Tree");
try
{
if (binaryTree != null)
{
int value1 = binaryTree.GetRootNode() != null?
binaryTree.GetRootNode().GetData() : -1;
int value2 = binaryTree.GetRootNode().GetLeftNode() != null?
binaryTree.GetRootNode().GetLeftNode().GetData() : -1;
int value3 = binaryTree.GetRootNode().GetRightNode() != null?
binaryTree.GetRootNode().GetRightNode().GetData() : -1;
if (value1 != -1 && value2 != -1)
{
binaryTree.GetRootNode().SetData(value2);
binaryTree.GetRootNode().GetLeftNode().SetData(value1);
}
else if (value1 != -1 && value3 != -1)
{
binaryTree.GetRootNode().SetData(value3);
binaryTree.GetRootNode().GetRightNode().SetData(value1);
}
Console.WriteLine("Modified BST is -----------");
TreeUtility.PrintTree(binaryTree.GetRootNode());
}
}
catch (Exception exception)
{
Console.WriteLine("Thrown exception is " + exception.Message);
}
return(binaryTree);
}
static void Main(string[] args)
{
Console.WriteLine("Correct a BST whose two nodes are swapped!");
Console.WriteLine("------------------------------------------");
BinaryTree binaryTree = ConstructTree();
try
{
Console.WriteLine("The input BST----------");
TreeUtility.PrintTree(binaryTree.GetRootNode());
Console.WriteLine();
binaryTree = TreeUtility.ModifyTree(binaryTree);
Console.WriteLine();
TreeUtility.CorrectBST(binaryTree.GetRootNode());
}
catch (Exception exception) {
Console.WriteLine("Thrown exception is " + exception.Message);
}
Console.ReadLine();
}