Data-structures/doubleLinkList.hpp at master · JasonEricZhan/Data-structures · GitHub

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//
//  doubleLinkList.hpp
//  double_link_list
//
//  Created by Eric on 2017/10/20.
//  Copyright © 2017年 Eric. All rights reserved.
//

#ifndef doubleLinkList_hpp
#define doubleLinkList_hpp

#include <stdio.h>
#include <iostream>
class node
{
public:
    friend class doubleLinkList;
private:
    node *prev;node *next;
    int value;
};


class doubleLinkList
{
public:
    doubleLinkList(){head=last=NULL;};
    doubleLinkList(int first_data){
        node *link = new node;
        link->value=first_data;
        link->next=link->prev=NULL;
        head=last=link;
    }
    void insertFirst( int data) {

        //create a link
        node *link = new node;
        link->value = data;

        if(!head) {

            last = link;
        } else {

            head->prev = link;
        }


        link->next = head;


        head = link;
    }

    void insertLast( int data) {

        //create a link
        node *link = new node;
        link->value = data;

        if(!last) {

            head = link;
        } else {

            last->next = link;

        }


        link->prev = last;


        last = link;
    }


    int deleteFirst() {

        //create a link
        int data=NULL;

        if(!head) {
            return data;
        } else {
            data=head->value;
            node *temp=head;
            head=head->next;
            delete temp;
        }
        return data;
    }


    int deleteLast() {

        //create a link
        int data=NULL;

        if(!last) {
            return data;
        } else {
            data=last->value;
            node *temp=last;
            last=last->prev;
            delete temp;
        }
        return data;
    }


private:
    node *head;
    node *last;

};
#endif /* doubleLinkList_hpp */