Thread: Binary Tree Problems

I followed a textbook example of how to implement a binary tree using template classes, but have needed to modify the (private) insert function to accept another treeNode * for the parent (I want to be able to remove nodes later), but the debugger has trouble getting past aRoot = new treeNode. With the first node, root points to 0 and Eclipse debugger says &aRoot = @0x0. I think it is trying to read memory from address 0 when it shouldn't be. Where I test if aRoot is 0, the program terminates if I don't use (&aRoot == 0). It used to work, but I cannot figure out what is wrong.

Code:

if (&aRoot == 0) { // was if (aRoot == 0) in the book

Code:

template<class treeElement>
bool binaryTree<treeElement>::insert(const treeElement &el) {
    treeNode *parent = 0;
    return insert(root, el, parent);
}

template<class treeElement>
bool binaryTree<treeElement>::insert(treeNode *&aRoot, const treeElement &el,
    treeNode *parent) {

    if (&aRoot == 0) {
        aRoot = new treeNode;
        aRoot->left = 0;     //doesn't execute
        aRoot->right = 0;
        aRoot->info = el;
        aRoot->parent = parent;
        return true;
    }
    else if (el == aRoot->info) return false;
    else if (el <= aRoot->info)
        return insert(aRoot->left, el, aRoot);
    else return insert(aRoot->right, el, aRoot);
}