Feb 20, 2014 at 6:42am
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/*DListNode1*/
/* DListNode1.java */
public class DListNode1 {
public Object item;
// public short[][] colorVal;
public DListNode1 prev;
public DListNode1 next;
DListNode1() {
item = 0;
prev = null;
next = null;
}
DListNode1(Object i) {
item = i;
prev = null;
next = null;
}
}
//////////////
/* Double linked list */
public class DList1 {
protected DListNode1 head;
protected DListNode1 tail;
protected long size;
public DList1() {
head = null;
tail = null;
size = 0;
}
public DList1(Object a) {
head = new DListNode1();
tail = head;
head.item = a;
size = 1;
}
public DList1(Object a, Object b) {
head = new DListNode1();
head.item = a;
tail = new DListNode1();
tail.item = b;
head.next = tail;
tail.prev = head;
size = 2;
}
public void insertFront(Object i) {
DListNode1 temp = new DListNode1(i);
if (size == 0) {
head = temp;
tail = temp;
}
else {
temp.next = head;
head.prev = temp;
head = temp;
} size++;
}
public void removeFront() {
if (size == 0) {
return;
}
else if (size == 1) {
head = null;
tail = null;
size--;
}
else {
head = head.next;
head.prev = null;
size--;
}
}
public String toString() {
String result = "[ ";
DListNode1 current = head;
while (current != null) {
result = result + current.item + " ";
current = current.next;
}
return result + "]";
}
/////////////
public static void main(String[] args) {
DList1 l = new DList1();
l.insertFront(9);
if (l.head.item != 9) {
System.out.println("head.item is wrong.");
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The line "if (l.head.item != 9" gave me the error it said something like object is not compatible with int. I am really confuse on why is that.
Last edited on Feb 20, 2014 at 6:45am
Feb 20, 2014 at 7:21am
this should a) be in the lounge b) be in the proper forum. does head have the member item?
Feb 20, 2014 at 9:23am
l.head.item, lets look at the classes of that construct: Dlist1.DListNode1.Object
Yeah, that's not an int...
You could either implement item as an int, or cast it to an int. Is there a reason you're using an Object class for item?
