Self Balancing AVL Tree memory leaks - c++

Question

So I've been working on this self-balancing AVL tree, and I feel like its working correctly, but there are some memory leaks. I've search and gone through a million times it feels like trying to figure out what I'm doing wrong but I'm new to this whole memory leak thing and obviously need to learn more. If anyone can help me out or can see where the leaks may be that would be awesome, here is the code for my AVL tree:
#pragma once
#include <algorithm>
#include <fstream>
#include "LinkedList.h"
template <typename ItemType>
class AVLTreeSet {
private:
struct Node {
ItemType info;
Node* left;
Node* right;
int height;
};
Node* root;
int size;
public:
AVLTreeSet()
{
root = NULL;
size = 0;
}
~AVLTreeSet()
{
clear();
}
void clear()
{
Node* n = root;
if(n != NULL)
{
clearTree(n->left);
clearTree(n->right);
delete n;
}
root = NULL;
}
void clearTree(Node* n)
{
if(n != NULL)
{
clearTree(n->left);
clearTree(n->right);
delete n;
}
}
void print(std::ofstream &out)
{
//cout << "HERE" << endl;
LinkedList<Node*> list;
int level = 0;
int levelSize;
int count = 0;
Node* n = root;
if (n == NULL)
{
return;
}
list.insert(n);
levelSize = list.getSize();
while(list.getSize() != 0)
{
count = 0;
out << "level " << level << ": ";
for (unsigned i = levelSize; i > 0; i--)
{
count++;
if (count > 8)
{
out << std::endl;
out << "level " << level << ": ";
count = 0;
}
n = list.getInfo();
out <<n->info << "(" << getHeight(n) << ") ";
if (n->left != NULL)
{
//cout << "left is not null" << endl;
list.insert(n->left);
}
if (n->right != NULL)
{
list.insert(n->right);
//cout << "right is not null" << endl;
}
list.remove();
}
levelSize = list.getSize();
level++;
out << std::endl;
//levelSize = list.getSize();
}
}
void insert(const ItemType& item)
{
//cout << "Insert FUNCTION" << endl;
Node* current = root;
if (current == NULL)
{
//cout << "ADD FUNCTION NULL" << endl;
current = new Node;
current->info = item;
current->left = NULL;
current->right = NULL;
current->height = 0;
root = current;
size++;
//cout << current->info << endl;
//cout << current->height << endl;
return;
}
if (current->info > item)
{
current->left = add(item, current->left);
}
if (current->info < item)
{
current->right = add(item, current->right);
}
current = balance(current);
root = current;
}
Node* add(const ItemType& item, Node* current)
{
if (current == NULL)
{
current = new Node;
current->info = item;
current->left = NULL;
current->right = NULL;
current->height = 0;
size++;
}
if (current->info > item)
{
current->left = add(item, current->left);
}
if (current->info < item)
{
current->right = add(item, current->right);
}
return current;
}
void remove(const ItemType& item)
{
Node* current = root;
if (current == NULL)
{
//cout << "NULL" << endl;
return;
}
if (current->info == item)
{
//cout << "FOUND" << endl;
current = removeNext(item, current);
current = balance(current);
root = current;
return;
}
if (current->info > item)
{
//cout << "LEFT" << endl;
current->left = removeNext(item, current->left);
if (current == root)
{
root = balance(current);
}
return;
}
if (current->info < item)
{
//cout << "RIGHT" << endl;
current->right = removeNext(item, current->right);
if (current == root)
{
root = balance(current);
}
return;
}
}
Node* removeNext(const ItemType& item, Node* current)
{
Node* temp;
if (current != NULL)
{
if (current->info > item)
{
//cout << "REMOVENEXT LEFT" << endl;
current->left = removeNext(item, current->left);
return current;
}
if (current->info < item)
{
//cout << "REMOVENEXT RIGHT" << endl;
current->right = removeNext(item, current->right);
return current;
}
//cout << "FOUND" << endl;
if (current->left != NULL && current->right != NULL)
{
//cout << "LEFT AND RIGHT CHILDREN" << endl;
temp = current;
current = CTR(current->right);
current->left = temp->left;
//cout << current->info << endl;
//looker = removeNext(current->info, temp->right);
delete temp;
size--;
current = balance(current);
return current;
}
else if (current->right != NULL)
{
//cout << "RIGHT ONE CHILD" << endl;
temp = current;
current = current->right;
delete temp;
size--;
current = balance(current);
return current;
}
else if (current->left != NULL)
{
//cout << "LEFT ONE CHILD" << endl;
temp = current;
current = current->left;
delete temp;
size--;
current = balance(current);
return current;
}
//cout << "CURRENT NODE" << endl;
delete current;
size--;
return NULL;
}
//cout << "NOT FOUND" << endl;
return current;
}
Node* CTR(Node* current)
{
while(current->left != NULL)
{
//cout << "ENTERED LOOP" << endl;
current = current->left;
}
//cout << current->info << endl;
return current;
}
bool find(const ItemType& item)
{
Node* current = root;
bool find = false;
if (current == NULL)
{
return find;
}
if (item == current->info)
{
find = true;
return find;
}
if (current->info > item && current->left != NULL)
{
find = findLeft(item, current->left);
}
if (current->info < item && current->right != NULL)
{
find = findRight(item, current->right);
}
return find;
}
bool findLeft(const ItemType& item, Node* current)
{
bool find = false;
if (item == current->info)
{
find = true;
return find;
}
if (current->info > item && current->left != NULL)
{
find = findLeft(item, current->left);
}
if (current->info < item && current->right != NULL)
{
find = findRight(item, current->right);
}
return find;
}
bool findRight(const ItemType& item, Node* current)
{
bool find = false;
if (item == current->info)
{
find = true;
return find;
}
if (current->info > item && current->left != NULL)
{
find = findLeft(item, current->left);
}
if (current->info < item && current->right != NULL)
{
find = findRight(item, current->right);
}
return find;
}
int getHeight(Node* temp)
{
int h = 0;
if (temp != NULL)
{
int l_height = getHeight(temp->left);
int r_height = getHeight(temp->right);
int max_height = std::max(l_height, r_height);
h = max_height + 1;
}
return h;
}
void setHeight(Node* n)
{
n->height = std::max(getHeight(n->right), getHeight(n->left)) + 1;
}
Node* balance(Node* n)
{
if (size == 1)
{
return n;
}
else if(getHeight(n->left) - getHeight(n->right) > 1) //n is out of balance
{
//cout << "BALANCE RIGHT" << endl;
n = balanceToRight(n);
}
else if(getHeight(n->right) - getHeight(n->left) > 1)
{
//cout << "BALANCE LEFT" << endl;
n = balanceToLeft(n);
}
return n;
}
Node* balanceToRight(Node* n)
{
if(getHeight(n->left->right) > getHeight(n->left->left))
{
n->left = rotateLeft(n->left); //<--- extra step for double rotate
}
n = rotateRight(n); //<--- this is for single
return n;
}
Node* balanceToLeft(Node* n)
{
if(getHeight(n->right->left) > getHeight(n->right->right))
{
n->right = rotateRight(n->right); //<--- extra step for double rotate
}
n = rotateLeft(n); //<--- this is for single
return n;
}
Node* rotateRight(Node* n)
{
Node* temp = n->left;
n->left = temp->right;
temp->right = n;
setHeight(n); //<--- set first
setHeight(temp);
return temp;
}
Node* rotateLeft(Node* n)
{
Node* temp = n->right;
n->right = temp->left;
temp->left = n;
setHeight(n); //<--- set first
setHeight(temp);
return temp;
}
};
I run the program by reading in a file with my main.cpp that calls the commands of my AVLtree. I know its a lot of code but I'm stressing out because I can't find where it maybe happening. Thanks.

Answer 1

How do you know that there are memory leak(s)?
Unless you use some tool to find the memory leak, for example valgrind as suggested by #jsantander, then try the following:
Avoid code duplication. There is too much of duplication in the present form. For example clear() could be simplified by just calling cleartree(root). Similar for insert().
Print/log memory each memory allocation (new) and deallocation (delete)
Keep always increasing counters, newCount and deleteCount. At the end of significant methods, add an assertion, assert( newCount - deleteCount == size );. At the first occurrence of memory leak, the assert() would blow. See http://accu.org/var/uploads/journals/overload102.pdf, page 7, "Other experiences"