Deleting node with two children in binary search tree

Question

I'm trying to delete a node with two children. However, my function is not completely removing the node from the tree, leaving a duplicate.

Here are my functions:

void Remove(Node *&r, int idx)
{
    if(Search(r, idx))
    {
        if(idx < r->id)      Remove(r->left, idx);
        else if(idx > r->id) Remove(r->right, idx);
        else                 DeleteNode(r);

        //cout << "Account " << idx << " is now closed.";
    }
    else cout << "Account does not exist." << endl;
}

void DeleteNode(Node *&r)
{
    Node *temp = r;

    if(r->left == NULL && r->right != NULL) 
    {
        r = temp->right;
        delete temp;
        temp = NULL;
    }
    else if(r->left != NULL && r->right == NULL) 
    {
        r = temp->left; 
        delete temp;
        temp = NULL;
    }
    else if(r->left == NULL && r->right == NULL)
    {
        r = NULL;
        delete r;
    }
    else 
    {
        // go to left of r and find largest value
        temp = FindMax(r->left);

        int    tempID        = temp->id; 
        float  tempBal       = temp->balance;
        string tempString    = temp->name; 

        DeleteNode(temp);   

        r->id = tempID; 
        r->balance = tempBal;
        r->name = tempString;
    }
}

Node* FindMax(Node *t)
{
    while(t->right != NULL) 
    {
        t = t->right;
    }
    return t;
}

Suppose I have this tree:

          33
    22          44 
11      25  

Deleting 22 leads to this:

          33
    22          44 
22      25  

Answer 1

temp = FindMax(r->left);

Not what you meant to do. When you DeleteNode(temp) , the old node is still in the tree but temp got overwritten. You meant to overwrite the parent's right member.