task 7 (ds lab 7) 3rd sem

#include<bits/stdc++.h>
using namespace std;
int y;
struct node
{
    int data;
    struct node* left;
    struct node* right;
};
typedef struct node Node;
Node* create_node(int item)
{
    Node* new_node=new Node();
    if(new_node==NULL)
        cout<<"Error"<<endl;
    else
    {
        new_node->data=item;
        new_node->left=new_node->right=NULL;
    }
    return new_node;
}
Node* insert_key(Node* x,int key)
{
    Node* new_node=create_node(key);
    if(x==NULL)
        return new_node;
    if(key>x->data+3)
    {
        x->right=insert_key(x->right,key);
    }
    else if(key<x->data-3)
    {
        x->left=insert_key(x->left,key);
    }
    else
        y=0;
    return x;
}
void printlevelorder(Node * x)
{
    if(x==NULL)
        return;
    queue<Node*>q;
    q.push(x);
    while(q.empty()==false)
    {
        Node* y=q.front();
        cout<<y->data<<" ";
        q.pop();
        if (y->left != NULL)
            q.push(y->left);
        if (y->right != NULL)
            q.push(y->right);
    }
}
Node * findmin(Node* node)
{
    Node* current = node;
    while (current && current->left != NULL)
        current = current->left;

    return current;
}
Node* deleteNode(Node* root, int key)
{
    if (root == NULL)
        return root;
    if (key < root->data)
        root->left = deleteNode(root->left, key);
    else if (key > root->data)
        root->right = deleteNode(root->right, key);
    else
    {
        Node *temp ;
        if (root->left == NULL)
        {
            temp = root->right;
            free(root);
            return temp;
        }
        else if (root->right == NULL)
        {
            temp = root->left;
            free(root);
            return temp;
        }

        temp = findmin(root->right);
        root->data = temp->data;
        root->right = deleteNode(root->right,temp->data);
    }
    return root;
}

int main()
{
    Node* root=NULL;
    y=1;
    while(1)
    {
        int n;
        cin>>n;
        if(n!=-1)
        {
            root=insert_key(root,n);
        }
        else
            break;
    }
    if(y==0)
        cout<<"All the inputs were not inserted."<<endl;
    int n;
    cin>>n;
    while(n--)
    {
        int key;
        cin>>key;
        deleteNode(root,key);
        printlevelorder(root);
        cout<<endl;
    }
}