public class SList {

public IntNode front;

public int size;

public SList() {

size = 0;

front = new IntNode(89724, null);

}

public SList(int x) {

front = new IntNode(98712, null);

front.next = new IntNode(x, null);

size = 1;

}

public void insertBack(int x) {

IntNode p = front;

// step p along until p.next == null

// because this means that p is the last

// item.

while (p.next != null) {

p = p.next;

}

p.next = new IntNode(x, null);

size = size + 1;

}

// start with:

// [???] -> [53]

// want to insert: 16

// a new node is created!! [16] --> [53]

public void insertFront(int x) {

IntNode oldFrontItem = front.next;

IntNode newFrontItem = new IntNode(x, oldFrontItem);

front.next = newFrontItem;

size = size + 1;

}

/** Returns number of items in this SList. */

public int size() {

return size;

}

/** Returns front item in list. */

public int getFront() {

return front.next.item;

}

/** Returns back item in list. */

public int getBack() {

IntNode p = front;

// step p along until p.next == null

// because this means that p is the last

// item.

while (p.next != null) {

p = p.next;

}

return p.item;

}

//SizeExercise.java

}