/* clist.cpp
 * Anthony Larrain
 *
 * An example of using a simple node struct to create a C-Style linked list.
 * The chaining of nodes is being done in main. 
 */

#include <iostream>
#include <cstdlib>

using namespace std;

struct node
{
    int data;
	node *next;
};

void printList(const node *cursor, ostream &out);
int size(const node *cursor);
void copyList(const node *cursor, node *&copyHead, node *&copyTail);

int main()
{
   
   //Creating two pointers
  	node *head, *tail;
   	head = tail = NULL;
   	
   /* Allocating memory for a node object(nameless)
      returning address to head
              --------
              |    |   |
      head -> |    |   |  
              -------- 
    */
	head = new node;	
	head -> data = 20;
	head -> next = NULL;
    tail = head;
    
   /*           ----------
       head->  |      |   |________
       tail->  |  20  |   |    |
               -----------     |  
                              ---          
                             ------
                             NULL  
    
    */
    printList(head, cout);  	
	
    /*
      allocating a new node object, returning the address and
      assigning it to tail's next field.
     */
    tail -> next = new node;
    
    // pointing tail to the newly created node object.  
    tail = tail -> next;        
    tail -> data = 30;
	tail -> next = NULL;	
    printList(head, cout);

    // adding another integer to the back of the list
   	tail -> next = new node;
    tail = tail -> next;
   	tail -> data= 10;
	tail -> next = NULL;	
    printList(head, cout);

    for(int i = 0; i < 5; i++) {
		tail -> next = new node;
		tail = tail -> next;
	    tail -> data = i * 3;
    	tail -> next = NULL;
    }
    printList(head, cout); 
    cout << "the size of the list is " << size(head) << endl;
    
    // insert a new node at the front
    node *newHeadNode = new node;
    newHeadNode -> data = 44;
    newHeadNode -> next = head;
    head = newHeadNode;
    printList(head, cout);
    
    // insert a new node at the back;
    node* newTailNode = new node;
    newTailNode->data=11111;
    newTailNode->next = NULL;
    tail->next = newTailNode;
    tail = newTailNode;
    printList(head, cout);  
    
    node *copyHead, *copyTail;
    copyList(head,copyHead,copyTail);
    printList(copyHead, cout);
    
    // change the copy
    copyHead -> data = 99999;
    printList(head, cout);
    printList(copyHead, cout);   
   
    system("pause");
    return 0;    	
}

void printList(const node *cursor, ostream &out)
{	
	while(cursor != NULL){
		out << cursor -> data <<" ";
		cursor = cursor -> next;
	}    
    out << endl;
	return;
}	
int size(const node *cursor)
{
    int count(0);
    //const node *cursor = hd;
    while(cursor != NULL){
        ++count;
        cursor = cursor -> next;
    }
    return count;
}
void copyList(const node *cursor, node *&copyHead, node *&copyTail)
{
    if(cursor == NULL) {
        return;
    }
    // copy first node
    copyHead = copyTail = new node;
    copyHead -> data = cursor -> data;
    copyHead -> next = NULL;
    cursor = cursor -> next;
    
    // add the rest to the end
    for(; cursor != NULL; cursor = cursor -> next){
        copyTail -> next = new node;
        copyTail = copyTail -> next;
        copyTail -> data = cursor -> data;
        copyTail -> next = NULL;
    }
}