<![CDATA[//************************ IntDLList.java ***************************/
public class IntDLList {
private IntDLLNode head, tail;
public IntDLList() {
head = tail = null;
}
public boolean isEmpty() {
return head == null;
}
public void setToNull() {
head = tail = null;
}
public int firstEl() {
if (!isEmpty())
return head.info;
else return 0;
}
public void addToDLListHead(int el) {
if (!isEmpty()) {
head = new IntDLLNode(el,head,null);
head.next.prev = head;
}
else head = tail = new IntDLLNode(el);
}
public void addToDLListTail(int el) {
if (!isEmpty()) {
tail = new IntDLLNode(el,null,tail);
tail.prev.next = tail;
}
else head = tail = new IntDLLNode(el);
}
public int deleteFromDLListHead() {
if (!isEmpty()) { // if at least one node in the list;
int el = head.info;
if (head == tail) // if only one node in the list;
head = tail = null;
else { // if more than one node in the list;
head = head.next;
head.prev = null;
}
return el;
}
else return 0;
}
public int deleteFromDLListTail() {
if (!isEmpty()) {
int el = tail.info;
if (head == tail) // if only one node on the list;
head = tail = null;
else { // if more than one node in the list;
tail = tail.prev;
tail.next = null;
}
return el;
}
else return 0;
}
public void printAll() { //OutputStream Out) {
for (IntDLLNode tmp = head; tmp != null; tmp = tmp.next)
System.out.print(tmp.info + " ");
}
public int find(int el) {
IntDLLNode tmp;
for (tmp = head; tmp != null && tmp.info != el; tmp = tmp.next);
if (tmp == null)
return 0;
else return tmp.info;
}
}
]]>