Stacks and Queues - Advanced Topics in Java: Core Concepts in Data Structures - page 119

int n = in.nextInt();
while (n != 0) {
S.push(new NodeData(n));
n = in.nextInt();
}
System.out.printf("\nNumbers in reverse order\n");
while (!S.empty())
System.out.printf("%d ", S.pop().getData());
System.out.printf("\n");
} //end main
} //end StackTest
class NodeData {
int num;
public NodeData(int n) {
num = n;
}
public int getData() {return num;}
public static NodeData getRogueValue() {return new NodeData(-999999);}
} //end class NodeData
class Node {
NodeData data;
Node next;
public Node(NodeData d) {
data = d;
next = null;
}
} //end class Node
class Stack {
Node top = null;
public boolean empty() {
return top == null;
}
public void push(NodeData nd) {
Node p = new Node(nd);
p.next = top;
top = p;
} //end push
public NodeData pop() {
if (this.empty())return NodeData.getRogueValue();
NodeData hold = top.data;