/**
* If PQ is non-empty, remove from PQ an item , X, of highest priority in PQ
*
* @return - highest priority item
*/
public ComparisonKey remove() {
ComparisonKey highestKey = null;
ListNode highestListNode = itemList.next;
if (highestListNode != null) {
highestKey = highestListNode.item;
ListNode nextHighestListNode = highestListNode.next;
// now reset the link
if (nextHighestListNode != null) {
itemList.next = nextHighestListNode;
} else {
itemList.next = null;
}
count--;
}
LOG.printDebugMessage("Removed highestKey=" + highestKey.toString());
return highestKey;
}
public void insert(ComparisonKey newKey) {
LOG.printDebugMessage("Insert " + newKey.toString());
if (isEmpty()) {
LOG.printDebugMessage("Adding first link!");
itemList.next = new ListNode(newKey, null);
} else {
// insert the new item in order so we maintain a sorted list
ListNode prevListNode = itemList;
ListNode currListNode = itemList.next;
boolean isInserted = false;
while (!isInserted) {
if (currListNode != null && newKey.compareTo(currListNode.item) >= 0) {
LOG.printDebugMessage("currListNode is null or newKey > currListNode.item");
ListNode newListNode = new ListNode(newKey, currListNode);
prevListNode.next = newListNode;
isInserted = true;
} else if (currListNode == null) {
LOG.printDebugMessage("reached the end of the linked list");
ListNode newListNode = new ListNode(newKey, null);
prevListNode.next = newListNode;
isInserted = true;
} else {
LOG.printDebugMessage("move to next pointer");
prevListNode = currListNode;
currListNode = currListNode.next;
} // if(currListNode==null)
} // while(!isInserted)
}
count++;
}