#include <iostream>

using namespace std;

struct node {
public:
    int d; // The data holder
    node * next; // A pointer to the next obj.
};

void Display();
void Init();
void AddEnd(int);
void AddBeg(int);
int ViewSeek(int);
void EditSeek(int, int);
int Dim();
void KillList();

// This is a pointer to the first object in the linked list
// (set to null, because there currently is none)
node * root = NULL;

int main() {
    Init();
    AddEnd(3);
    AddEnd(8);
    AddBeg(5);
    cout << "View Seek: " << ViewSeek(1) << endl;
    cout << "Counter: " << Dim() << endl;
    Display();
    EditSeek(3, 2);
    cout << endl;
    Display();
    KillList();

    system( "PAUSE" );
    return 0;
}

// Displays the linked list (excluding the root)
void Display() {
    node * ptr = root; // Temperary pointer, for following the list until the end
    while (ptr -> next != NULL) {
        ptr = ptr -> next;
        cout << ptr -> d << endl;
    }

    return;
}

// Initalizes the root object
void Init() {

    root = new node;
    root -> next = NULL;
    root -> d = 0;
    return;
}

// Adds a new object to the end of the list, and assigns the value of 'num'
// to the 'd' variable
void AddEnd(int num) {
    node * ptr = root; // Temperary pointer, for following the list until the end

    while (ptr -> next != NULL) {
        ptr = ptr -> next;
    }
    if (ptr -> next == NULL) {
        ptr -> next = new node;
        ptr = ptr -> next;
        ptr -> d = num;
    }
    return;
}

// Adds a node after the root, and makes 'd' have the passed value, num
void AddBeg(int num) {
    node * ptr = new node;
    ptr -> next = root -> next;
    ptr -> d = num;
    root -> next = ptr;
}

// This function finds the value in the node # (nodeNum),
// assuming 0 is root (nothing in root)
// Returns 0, if the location doesn't exist
int ViewSeek(int nodeNum) {
    int j = 1; // The counter, to keep track on witch node its on
    node * ptr = root; // Used to go from node to node
    for (j = 1;j <= nodeNum;j++) {
        if (ptr -> next == NULL) {
            return 0;
        }
        else {
            ptr = ptr -> next;
        }
    }
    return ptr -> d;
}

// Finds the desired node on the list, and edits its 'd' variable
// nodeNum - node to edit (assume 0 is root)
// num - the number to replace 'd'
void EditSeek(int nodeNum,int num) {
    int j = 1; // The counter, to keep track on witch node its on
    node * ptr = root; // Used to go from node to node
    for (j = 1;j <= nodeNum;j++) {
        if (ptr -> next == NULL) {
            return;
        }
        else {
            ptr = ptr -> next;
        }
    }
    ptr -> d = num;
}

// Returns the # of nodes in the linked list (excluding the root)
int Dim() {
    node * ptr = root;

    int counter = 0; // Keeps track of the # of nodes

    while(ptr -> next != NULL) {
        counter++;
        ptr = ptr -> next;
    }
    return counter;

}

// Deletes all the nodes in the List
// Starts at the root, but doesn't delete the root, deletes the next node,
// And has the root points to the one after that
// At the very end, the root is deleted
void KillList() {
    node * ptr = root; // Temperary pointer

    while ((ptr -> next != NULL) && (root -> next != NULL)) {
        ptr = ptr -> next;
        if (ptr -> next != NULL) {
            root = ptr -> next; // make root point to the next node
        }
        else {
            root -> next = NULL;
        }
        delete ptr; // get rid of lost node
        ptr = root;

    }
    delete root; // finish off the list, by killing the root
    return;
}