// Demonstrate implementation of preorder and postorder using a stack.

class StackRecord {
   public AnimalGroup1 element;  // Element on stack
   public int indent;            // How deep to indent
   public int state =0;          // How many children have been explored

   public StackRecord(AnimalGroup1 e, int i) {
      element = e; indent = i;
     }
}


public class StackTreeTraversal2{

    public static void displayNode(StackRecord r) {
           for (int i=0; i<r.indent; i++) System.out.print(" ");
           System.out.println(r.element.getLabel());
         }

    public static void preorderDisplay(AnimalGroup1 A) {
         MyStack<StackRecord> stack = 
            new MyStack<StackRecord>(new StackRecord[200]);
         stack.push(new StackRecord(A,0));
         while (! stack.isEmpty()) {
           StackRecord r = stack.top();
           if (r.state==0) displayNode(r);
           AnimalGroup1 e = r.element;
           if (r.state == e.getNumChildren()) 
             stack.pop();
           else {
             stack.push(new StackRecord(
                               e.getChildren()[r.state], r.indent+3));
             r.state++;
            }
         }
     }     

    public static void postorderDisplay(AnimalGroup1 A) {

         MyStack<StackRecord> stack = 
            new MyStack<StackRecord>(new StackRecord[200]);
         stack.push(new StackRecord(A,0));
         while (! stack.isEmpty()) {
           StackRecord r = stack.top();
           AnimalGroup1 e = r.element;
           if (r.state == e.getNumChildren()) {
             displayNode(r);
             stack.pop();
             }
           else {
             stack.push(new StackRecord(
                               e.getChildren()[r.state], r.indent+3));
             r.state++;
            }
         }
     }     

    public static void main(String args[]) {
       AnimalGroup1 Mammal = AnimalGroup1.Taxonomy1();
       System.out.println(" ************   PREORDER ***************");
     
       preorderDisplay(Mammal);
       System.out.println("\n ************   POSTORDER ***************");
       postorderDisplay(Mammal);
     }
}