#ifndef LIST_H
#define LIST_H

typedef int EType ;
typedef int Position;

class List {
public:
    List();
    void insert(EType x, Position p);
    void remove(Position p);

    bool isEmpty() const;

    Position locate(EType x) const;
    EType retrieve(Position p) const;

    Position first() const;
    Position end() const;
    Position next(Position p) const;
    Position previous(Position p) const;

    void clear();

    void print() const;
private:
    static const int MAX_SIZE = 100;
    int array[MAX_SIZE];
    int length;
};

#endif
#include <iostream>
#include <cstdlib>
#include "list.h"

using namespace std;

void List::insert(EType x, Position p){
    if(p<first() || p>end())
        cout<<"Error insert"<<endl;
    for(Position i=previous(end());i>=p;i=previous(i))
        array[next(i)]=retrieve(i);
            array[p]=x;
            length;
            }
void List::remove(Position p){

    }



bool List::isEmpty() const{
    bool empty=false;
    for(int i=0;i<MAX_SIZE;i++){
        if(length==0)
            empty=true;
}
return empty;
}

Position List:: locate(EType x) const{
    Position p=first();
    while(p!=end()){
        if(retrieve(p)==x)
            return p;
    }
}
EType List:: retrieve(Position p) const{
    Position x=first();
    while(x!=end()){
        if(retrieve(x)==p)
            return x;
    }
}

Position List::first() const{
    return 0;
}
Position List::end() const{
    return length;
}
Position List::next(Position p) const{
    if(p>=end())
        cout<<"Error"<<endl;
    return p+1;
}
Position List::previous(Position p) const{
    if(p<=first())
        cout<<"Error"<<endl;
    return p-1;
}
void List::clear(){
    for(int i=0;i<MAX_SIZE;i++){
        array[i]=0;
    }
}
void List::print() const{
    bool empty=false;
    for(int i=0;i<MAX_SIZE;i++){
        if(array[i]!=first()){
            cout<<"Position: "<<i+1<<". "<<array[i]<<endl;
        }
}
if(empty==true){
    cout<<"The list is empty"<<endl;
}
}