doubly linked list implementation

#include<iostream>
using namespace std;
class dlist{
    public:
        int data;
        dlist*right;
        dlist*left;
        dlist(int n){
            this->data=n;
            left=NULL;
            right=NULL;
        }
};
void print(dlist*tmp){
    while(tmp){
        cout<<tmp->data<<" ";
        tmp=tmp->right;
    }
    cout<<endl;
}

void push(dlist* &node,int n){
    dlist*tmp=new dlist(n);
    tmp->right=node;
    node->left=tmp;
    node=tmp;
}

void deletenode(dlist* &node,int x){
    if(!node)return;
    if(node->data==x){
        node=node->right;
        node->left=NULL;
        return;
    }
    dlist*tmp=node;
    while(tmp->right!=NULL && tmp->right->data != x){
        tmp=tmp->right;
    }
    if(tmp->right){
        tmp->right=tmp->right->right;
        if(tmp->right)tmp->right->left=tmp;
    }
}
void reverse(dlist* &node){
    if(!node || !node->right)return;
    dlist*curr=node,*prev=NULL;
    while(curr){
        dlist*next=curr->right;
        curr->right=prev;
        curr->left=next;
        prev=curr;
        curr=curr->left;
    }
    node=prev;
}
void middle(dlist* node){
    if(!node)cout<<-1<<endl;
    else if(!node->right)cout<<node->data<<endl;
    else{
        dlist*slow=node,*fast=node->right;
        while(fast && fast->right){
            slow=slow->right;
            fast=fast->right->right;
        }
        cout<<slow->data<<" ";
        if(fast)cout<<slow->right->data<<" ";
        cout<<endl;
    }
}
int main(){
    dlist*head=new dlist(0);
    push(head,1);
    push(head,2);
    push(head,4);
    push(head,5);
    push(head,6);
    print(head);
    deletenode(head,3);
    print(head);
    deletenode(head,0);
    print(head);
    deletenode(head,6);
    print(head);
    reverse(head);
    print(head);
    middle(head);
    push(head,7);
    print(head);
    middle(head);
}