Question

This question is related to a Binary Search tree. Here is the definition of a node that I am using

struct _Node
{
    _Node *Parent;
    int Data;
    _Node *Left;
    _Node *Right;
};

Now here is the definition of the function to add a node once a root is created

void AddNode(_Node *Incoming, _Node *currentNode)
{

            if(!currentNode)
            {
                currentNode = Incoming;
            }
            else if(currentNode->Data >= Incoming->Data)
            {
                Incoming->Parent = currentNode;
                AddNode(Incoming, currentNode->Left);
            }
            else if(currentNode->Data < Incoming->Data)
            {
                Incoming->Parent = currentNode;
                AddNode(Incoming, currentNode->Right);
            }

}

AddNode function is based on a recursive approach. Main code is

_Node *Root= new _Node;
Root->Data = 50;
Root->Parent = nullptr;
Root->Left = nullptr;
Root->Right = nullptr;


_Node *Node2 = new _Node;
Node2->Data = 25;
Node2->Parent = nullptr;
Node2->Left = nullptr;
Node2->Right = nullptr;
_Node *Node3 = new _Node;

   AddNode(Node2, Root);

Problem:
Once I come out of the add node function I find that Root node doesnot have a Left or Right Child set to Node2. According to me as pointer to a node is passed each time I should have got the node added to the Root correctly. this is not happening. Can you please help me out here to understand what mistake I am making?

Answer 1

Try

AddNode(Incoming, currentNode->Left);

instead of

AddNode(Incoming, Incoming->Left);

Same for Right.