how do you create an Insert function for Binary search tree using nodes as parameters?

Question

I just started my second C++ class and am struggling to grasp the concept of nodes and linked lists. Every insert function I've found for binary trees uses either an int as a parameter, or an int an a node. Example:

  Node* InsertNode(Node* root, int data)
{
    // If the tree is empty, assign new node address to root
    if (root == NULL) {
        root = CreateNode(data);
        return root;
    }
 
    // Else, do level order traversal until we find an empty
    // place, i.e. either left child or right child of some
    // node is pointing to NULL.
    queue<Node*> q;
    q.push(root);
 
    while (!q.empty()) {
        Node* temp = q.front();
        q.pop();
 
        if (temp->left != NULL)
            q.push(temp->left);
        else {
            temp->left = CreateNode(data);
            return root;
        }
 
        if (temp->right != NULL)
            q.push(temp->right);
        else {
            temp->right = CreateNode(data);
            return root;
        }
    }

But this practice problem requires two nodes as parameters.

function (Insert(Node *insert_node, Node *tree_root){
} 

This is the full code:

#include <iostream>
#include <cstddef>

using std::cout;
using std::endl;

class Node {
    int value;
public:
    Node* left;       // left child
    Node* right;      // right child
    Node* p;          // parent
    Node(int data) {
        value = data;
        left = NULL;
        right = NULL;
        p  = NULL;
    }
    ~Node() {
    }
    int d() {
        return value;
    }
    void print() {
        std::cout << value << std::endl;
    }
};


int main(int argc, const char * argv[])
{
    
}

function insert(Node *insert_node, Node *tree_root){
    //Your code here
}

function delete_node(int value, Node *tree_root){
    //Your code here
}

function search(int value, Node *tree_root){
    //Your code here
}

I don't know why I'm struggling with these concepts so much. Can anyone point out the right direction?

Answer 1

You have Node objects with a member called data which is an int .

You have not given your full insert (with numeric parameter), so I will only give you an idea of how you can refactor that:

• the very first line should be int data = insert_node->data; , so later on data will have the correct value
• instead of temp->left = CreateNode(data); or temp->right = CreateNode(data); , you will need temp->left = insert_node; and temp->right = insert_node; , respectively, as you already have a node to work with, no need to create one
• pay attention to tree_root , earlier it was called root