Doubly linked list

#include<iostream>
using namespace std;

struct node{
    float data;
    node *next;
    node *prev;
};

class doublelinkedlist{
    node *head;
public:
    doublelinkedlist(){
        head=NULL;
    }

void insertatbegin(int d){
        node *nn=new node;
        nn->data=d;
        nn->prev=NULL;
        nn->next=head;
        if(head)
            {
            head->prev=nn;
            }
        head=nn;
    }

void insertatend(int d){
        node *nn=new node;
        nn->data=d;
        nn->next=NULL;
        nn->prev=NULL;
        node *t=head;
        while(t->next){
            t=t->next;
        }
        t->next=nn;
        nn->prev=t;
    }

void display(){
        node *t=head;
        while(t!=NULL){
            cout << t->data <<" -> ";
            t=t->next;
        }
        cout<<"NULL\n";
    }

void deleted(int v)
    {
        node *t=head;
        while(t->data!=v && t!=NULL){
            t=t->next;
        }
        if(t->prev){
            t->prev->next=t->next;
        }
        if(t->next){
            t->next->prev=t->prev;
        }
        free(t);
    }

void displayreverse(){
        node *t = head;
        while(t -> next != NULL){
            t = t -> next;
        }
        while(t != NULL){
            cout << t->data <<" -> ";
            t=t->prev;
        }
        cout << "NULL" << endl;
    }

void deletionAtBegin(){
        node *t = head;
        if(t == NULL){
            cout << "Empty list" << endl;
        }
        else{
            head = head -> next;
            if(head != NULL){
                head -> prev = NULL;
            }
            free(t);
        }
    }

void deletionAtEnd(){
        node *t = head;
        while(t -> next != NULL){
            t = t-> next;
        }
        if(t -> prev != NULL){
            t -> prev -> next = NULL;
            free(t);
        }
        else{
            free(t);
            head = NULL;
        }
}

void insertAtPos(){
    node *nn = new node;
    int n, pos;
    cout << "Enter a data part and position respectively:" << endl;
    cin >> n;
    cin >> pos;
    nn -> data = n;
    nn -> next = NULL;
    nn -> prev = NULL;
    if(head == NULL){
        insertatbegin(n);
    }
    else{
        int i = 0;
        node *p = head;
        while(i != pos -2){
            p = p -> next;
            i++;
        }
        nn -> next = p -> next;
        p -> next = nn;
        nn -> prev = p;
    }
}

void insertAftervalue(int v, int aftervalue);
};


int main(){
    int ch=0,v1=0;
    doublelinkedlist d;
    do{
        cout<<"1: Insert element at beginning\n";
        cout<<"2: Insert element at Ending\n";
        cout<<"3: Delete element \n";
        cout<<"4: Print in reverse order\n";
        cout<<"5: Delete at beginning\n";
        cout<<"6: Delete at end\n";
        cout<<"7: Insert after value\n";
        cout<<"0: Exit\n";
        cout<<"Enter choice" << endl;
        cin>>ch;
        switch(ch){
        case 1:
            cout<<"\nEnter the element to insert at the beginning:" << endl;
            cin>>v1;
            d.insertatbegin(v1);
            d.display();
            break;
        case 2:
            cout<<"\nEnter the element want to be at end:" << endl;
            cin>>v1;
            d.insertatend(v1);
            d.display();
            break;
        case 3:
            cout<<"\nEnter the element to be delete:" << endl;
            cin>>v1;
            d.deleted(v1);
            d.display();
            break;
        case 4:
            cout<<"\nList in reversed order is:" << endl;
            d.displayreverse();
            break;
        case 5:
            d.deletionAtBegin();
            d.display();
            break;
        case 6:
            d.deletionAtEnd();
            d.display();
            break;
        case 7:
            d.insertAtPos();
            d.display();
            break;
        }
    }while(ch!=0);
}