//
// Created by dongl on 22-9-20.
//


#ifndef CPP_LINKLIST_H
#define CPP_LINKLIST_H
#include <iostream>
#endif //CPP_LINKLIST_H

template<typename U>
class LNode{
public:
    U data;

    LNode<U> *next = nullptr;

    LNode(): next(nullptr){

    }
    void update(U el){
        data = el;
    }
};

template<typename T>
class List{
    LNode<T> *lNode = new LNode<T>;
    unsigned int _length = 0;
    LNode<T>* _begin = lNode;
public:
    List(){

    }
    void add(T el){
        lNode = lNode->next = new LNode<T>;
        lNode->data = el;
        _length++;
        lNode->next = new LNode<T>;
    };

    int get(T index){
        int el;
        LNode<T>* node = _begin;
        for (int i = 0; i < index; ++i) {
            node = node->next;
            el = node->data;
        }
        return el;
    }

    void remove(unsigned int index){
        if(index > _length+1)
            std::cerr << "超越范围之外:" << __FILE__ <<
            ":" <<__LINE__ <<std::endl;

        LNode<T>* begin = _begin;
        for (int i = 1; i < index; ++i) {
            begin = _begin->next;
        }

        LNode<T>* node = begin->next;
        begin->next = begin->next->next;
        delete node;
        _length--;
    }

    void update(int index, T el){
        LNode<T>* node;
        for (int i = 0; i < index; ++i) {
           node = _begin->next;
        }
        node->data = el;
    }

    int length(){
        return _length;
    }

    LNode<T>*& begin(){
       return _begin->next;
    }
};