CODEWITHSUNDEEP
recursionnullc++14binary-search-treenodes
tsalemy
tsalemy

Reputation: 1

Binary Search Tree Insert Implementation

So my question is as follows: When I run the code for this insert helper method, and I am positive my new node method is correct as it works for instantiating a Binary Search Tree, no nodes are inserted. Why can't I use this certain implementation? What's going wrong here?

I know how to use the other insert implementation where one would check for the left and right nodes of the root and whether or not they are null, but can not figure out the problem of this more elegant possibility. The answer to this will help me in creating other functions that go beyond the scope of the insert function.

btw yes I have another function calling this helper function

Thanks!!!!!

//INSERT METHODS
void BinarySearchTree::insert(int data, struct node* root) {
//If root is null make new node there
if (!root) {
    root = new node(data);

}
else if (root -> data > data) {
    insert(data, root -> left);
}
else {
    insert(data, root -> right);
}

}

Upvotes: 0

Views: 289

Answers (1)

Mark
Mark

Reputation: 1498

The variable root is a parameter, which only has local visibility for that one method call. Meaning root = new node(data) will indeed create a new node, but that will only be pointed to by the parameter. Your method doesn't return anything and it doesn't actually know what it is supposed to do with that new root object of yours (it is NOT the same as any class variable you might have defined that is named the same).

So you create a new node, but can't use it outside that one method call. Which results in an empty tree.

As a side note for future questions: Include a tag for the programming language you are using. A lot of people use that as a filter, so you will actually get more people looking at this if you use the right tag.

Upvotes: 1

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