task 6 (ds lab 7) 3rd sem

#include<bits/stdc++.h>
using namespace std;
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)
        x->right=insert_key(x->right,key);
    else if(key<x->data)
        x->left=insert_key(x->left,key);
    return x;
}
int maxpath(Node *q, int x)
{
    Node *p=q;
    int mx=INT_MIN;
    while(p->data!=x)
    {
        if(p->data>x)
        {
            mx=max(mx,p->data);
            p=p->left;
        }
        else
        {
            mx=max(mx,p->data);
            p=p->right;
        }
    }
    return max(mx,x);
}
Node* lca(Node* root, int x, int y)
{
    if(root == NULL)
        return NULL;
    if(root->data>x && root->data>y)
        return lca(root->left,x,y);
    if(root->data<x && root->data<y)
        return lca(root->right,x,y);

    return root;
}
int maxelement(Node* root,int x,int y)
{
    Node *p;
    p=lca(root,x,y);
    return max(maxpath(p,x),maxpath(p,y));
}
int main()
{
    Node* root=NULL;
    while(1)
    {
        int n;
        cin>>n;
        if(n!=-1)
            root=insert_key(root,n);
        else
            break;
    }
    int n;
    cin>>n;
    while(n--)
    {
        int x,y;
        cin>>x>>y;
        cout<<maxelement(root,x,y)<<endl;
    }
}