binary tree and AVL tree unhandled exception

[cyrus mortis]

Hello,

I am working on a tree and AVL tree program and I have everything done, but It crashes when run (no compiling errors) so i run it in debug through visual studios and it says:

Unhandled exception at 0x004018C9 in p-tree.exe: 0xC0000005: Access violation reading location 0x51BAA9F4.

I have no idea what to do.. debugging was only briefly and not very well covered in my class. Any help would be appreciated!

if I comment out the printTree in main() it runs fine, so not sure if the problem is there or just doesn't become issue until then.

My code:

                #include<iostream>
                #include<fstream>
                #include<vector>
                #include<iomanip>

                using namespace std;

                struct binaryNode{

                    int height;
                    int value;
                    binaryNode *left;
                    binaryNode *right;

                };//end node

                int findHeight(binaryNode* root){
                        if(&root == nullptr){
                        return 0;
                    }else{
                        int l = findHeight(root->left);
                        int r = findHeight(root->right);
                        return max(l,r) + 1;
                    }
                };//end findHeight

                void insertNode(binaryNode* head, int x){
                    int depth;

                    if(head == NULL){
                        head = new binaryNode;
                        head->height = findHeight(head);
                        head->value = x;
                    }else if(x < head->value){
                        insertNode(head->left, x);
                    }else if(x > head->value){
                        insertNode(head->right, x);
                    }else{};//end if else
                };//end create tree

                void rotateWithLeftChild(binaryNode* k2){

                    binaryNode* k1 = k2->left;
                    k2->left = k1->right;
                    k1->right = k2;
                    k2->height = max(findHeight(k2->left), findHeight(k2->right)) + 1;
                    k1->height = max(findHeight(k1->left), k2->height) + 1;
                    k2 = k1;
                };//end rotate with left child

                void rotateWithRightChild(binaryNode* k1){

                    binaryNode *k2 = k1->right;
                    k1->right = k2->left;
                    k2->left = k1;
                    k1->height = max(findHeight(k1->left), findHeight(k1->right)) + 1;
                    k2->height = max(findHeight(k2->right), k1->height) + 1;
                    k1 = k2;

                }; // end with rotate with right child

                void doubleWithLeftChild(binaryNode* k3){
                    rotateWithRightChild(k3->left);
                    rotateWithLeftChild(k3);

                }; //end double with left child

                void doubleWithRightChild(binaryNode* k1){
                    rotateWithLeftChild(k1->right);
                    rotateWithRightChild(k1);
                }

                void insertAVLtree(binaryNode* head, int x){

                    int height;

                    if(head == NULL){
                        head = new binaryNode;
                        head->height = findHeight(head);
                        head->value = x;
                    }else if(x < head->value){
                        insertAVLtree(head->left, x);
                        if((findHeight(head->left) - findHeight(head->right)) == 2){
                            if(x < head->left->value){
                                rotateWithLeftChild(head);

                            }else{
                                doubleWithLeftChild(head);
                            }
                        }
                    }else if(head->value < x){
                        insertAVLtree(head->right, x);
                        if((findHeight(head->right) - findHeight(head->left) == 2)){
                            if(head->right->value < x){
                                rotateWithRightChild(head);
                            }else{
                                doubleWithRightChild(head);
                            }
                        }//end if height
                    }else{
                        head->height = max(findHeight(head->left), findHeight(head->right)) + 1;
                    }

                };//end insertAVL

                void printTree(binaryNode* head, int indent=0){
                    if(head != NULL){
                        if(head->left != NULL){
                            printTree(head->left, indent + 4);
                        }
                        if(head->right != NULL){
                            printTree(head->right, indent + 4);
                        }
                        if(indent){
                            cout << setw(indent) << " ";
                        }
                        cout << head->value << "\n";
                    }
                };//end print tree

                main(){

                vector<int> fileArray;
                int number;

                ifstream file; //create stream
                file.open("treenode.txt"); //open file


                if(file.is_open()){
                    while(file >> number){

                        fileArray.push_back(number);
                        char comma;
                        file >> comma;
                    }
                }

                file.close();//close file

                binaryNode* head;
                binaryNode* headAVL;

                for(int i = 0; i < fileArray.size(); i++){
                    insertNode(head, fileArray[i]);
                }
                for(int j = 0; j < fileArray.size(); j++){
                    insertAVLtree(headAVL, fileArray[j]);
                }

                printTree(head);
                printTree(headAVL);

                };//end main 

[goldenchicken]

I got some warnings cpp.sh generated from this code:

In function 'int findHeight(binaryNode*)':
19:37: warning: the address of 'root' will never be NULL [-Waddress]
In function 'void insertNode(binaryNode*, int)':
29:25: warning: unused variable 'depth' [-Wunused-variable]
In function 'void insertAVLtree(binaryNode*, int)':
76:25: warning: unused variable 'height' [-Wunused-variable]
At global scope:
122:22: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
In function 'int main()':
145:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
148:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
152:32: warning: 'head' may be used uninitialized in this function [-Wmaybe-uninitialized]
149:57: warning: 'headAVL' may be used uninitialized in this function [-Wmaybe-uninitialized]

Maybe the problem has something to do with this

[Thomas1965]

I think the problem starts with

  binaryNode* head;
  binaryNode* headAVL;
  for(int i = 0; i < fileArray.size(); i++){
    insertNode(head, fileArray[i]);
 }

head points to a random location and when you try to use it in insertNode (line 35 or 37) this causes the crash.

Some material about debugging:
http://www.cprogramming.com/debugging/debugging_strategy.html
https://www.amazon.co.uk/Effective-Debugging-Specific-Software-Development/dp/0134394798/ref=pd_cp_14_1?_encoding=UTF8&psc=1&refRID=9QNN85SZHNEB0863KXJM