<![CDATA[/*********************** SLList.java ***************************
* generic singly linked list class with head only
*/
public class SLList {
protected SLLNode head = null;
public SLList() {
}
public void setToNull() {
head = null;
}
public boolean isEmpty() {
return head == null;
}
public Object first() {
return head.info;
}
public SLLNode head() {
return head;
}
public void printAll(java.io.PrintStream out) {
for (SLLNode tmp = head; tmp != null; tmp = tmp.next)
out.print(tmp.info.toString());
}
public void add(Object el) {
head = new SLLNode(el,head);
}
public Object find(Object el) {
SLLNode tmp = head;
for ( ; tmp != null && !el.equals(tmp.info); tmp = tmp.next);
if (tmp == null)
return null;
else return tmp.info;
}
public Object deleteHead() { // remove the head and return its info;
Object el = head.info;
head = head.next;
return el;
}
public void delete(Object el) { // find and remove el;
if (head != null) // if non-empty list;
if (el.equals(head.info)) // if head needs to be removed;
head = head.next;
else {
SLLNode pred = head, tmp = head.next;
for ( ; tmp != null && !(tmp.info.equals(el));
pred = pred.next, tmp = tmp.next);
if (tmp != null) // if found
pred.next = tmp.next;
}
}
}
]]>