#include <iostream>
#include <iomanip>
#include "list.h"

List::List() {
    int i;

    head = NIL;
    free = 0;

    for(i=0;i<MAX_LENGTH-1;i++) {
        datalist[i].next = i+1;
    }
    datalist[MAX_LENGTH-1].next = NIL;
}

bool List::IsEmpty() const{
   return(head==NIL);
}

bool List::IsFull() const{
   return(free==NIL);
}

int  List::Length() const{
   int count=0;
   int tmp;

   tmp = head;
   while(tmp != NIL) {
      count++;
      tmp = datalist[tmp].next;
   }

   return(count);
}

void List::Insert(ItemType item){
   int tmp;

   if (free == NIL) {
      cout << "The list is full, can't insert" << endl;
      return;
   }
   // grab a node from the free list

   tmp = free;
   free = datalist[tmp].next;

   // fill in the data in the new node
   datalist[tmp].data = item;

   // insert the node into the data list
   datalist[tmp].next = head;
   head = tmp;
}

void List::Delete(ItemType item){
    int tmp, prev;

    tmp = NIL;

    if (head == NIL) {
      return;
    }
    // check for first item in the list
    if (datalist[head].data == item) {
        tmp = head;
        head = datalist[head].next;
        datalist[tmp].next = free;
        free = tmp;
        return ;
    }

    tmp = datalist[head].next;
    prev = head;

    while ((tmp != NIL) && (datalist[tmp].data != item)) {
        prev = tmp;
        tmp = datalist[tmp].next;
    }
    if (tmp != NIL) {
        datalist[prev].next = datalist[tmp].next;
        datalist[tmp].next = free;
        free = tmp;
    }

}

bool List::IsPresent(ItemType item) const {
   int tmp;

   tmp = head;
   while((tmp != NIL) && (datalist[tmp].data != item)) {
      tmp = datalist[tmp].next;
   }

   if ((tmp != NIL) && (datalist[tmp].data == item)) {
      return(true);
   } else {
      return(false);
   }

   return(tmp != NIL);
}

void List::Print() const{
   int tmp;

   tmp = head;
   while(tmp != NIL) {
      cout << datalist[tmp].data << endl;
      tmp = datalist[tmp].next;
   }
}

void List::PrintFreelist() {
     int tmp;

     if (free == NIL) {
        cout <<  "Thre are no nodes in the free list " << endl;
     } else {
        cout << "The nodes in the free list are : " << endl;
        tmp = free;
        while (tmp != NIL) {
           cout << tmp << endl;
           tmp = datalist[tmp].next;
        }
     }
}

void List::PrintDS() {
    int  i;

    cout << "Head = " << head << endl;
    cout << "Free = " << free << endl;

    for(i=0;i<MAX_LENGTH;i++) {
        cout << i << setw(15) << datalist[i].data
	          << setw(15) << datalist[i].next << endl;
    }
}