#ifndef LINKED_LIST_H
#define LINKED_LIST_H

#include <string>

using namespace std;

class linked_list {
public:
    // construct an empty list
    linked_list();

    // copy constructor
    linked_list(const linked_list & rhs);

    // destructor
    ~linked_list();

    // appends given value to end of list
    void add(int data);

    // returns bracketed, comma-separated version of list
    string to_string() const;  

    // returns true if list contains the given value
    bool contains(int value) const;

    // returns the number of elements in the list
    int size() const;

    // removes all elements of the list, leaving it empty
    void clear();

    // overloaded assignment operator
    linked_list & operator=(const linked_list & rhs);

    // const version of the overloaded [] operator
    const int & operator[](int index) const;

    // non-const version of the overloaded [] operator
    int & operator[](int index);
private:
    struct list_node;
    list_node * front;
    list_node * back;
    int count;
    void delete_nodes(list_node * current);
    void copy_from(list_node * other);
    list_node * node_at(int index) const;
};

void print(const linked_list & list);

#endif