GIQ: depth-first graph traversal

Describe the algorithm for a depth-first graph traversal.

The use of a Stack and a Node with children...
The stack is used to traverse the tree of nodes.

import java.util.*;
public class depthfirst {

  public class Node {
    Object o;
    Collection children;
    Node(Object o) {this.o=o; children=new ArrayList();}
  }
  Node tree = null;
  Stack stack = new Stack();

  /* Push input node into Stack 
   * Store input node in 'node'
   * Loop until stack is not empty:
   *   Pop stack into 'node'
   *   Print Node Data 
   *   Push all child nodes into Stack 
   */
  void depthFirstTraversal(Node node) { 
    if (node == null) return; 
    stack.push(node); 
    while(!stack.empty()) { 
      node = (Node) stack.pop(); 
      System.out.println("Next: "+node.o); 
      for(Iterator i=node.children.iterator(); i.hasNext(); ) {
        Node next = (Node) i.next();
        stack.push(next);
      } 
    }
  }

  void breadthFirstTraversal(Node node) { 
    if (node == null) return; 
    list.add(node); 
    while(!list.isEmpty()) { 
      node = (Node) list.remove(); 
      System.out.println("Next: "+node.o); 
      for(Iterator i=node.children.iterator(); i.hasNext(); ) {
        Node next = (Node) i.next();
        list.add(next);
      } 
    }
  }

  public depthfirst(){
  }

  public void init() {
    System.out.println(""+getAppletInfo());
    System.out.println("depthfirst:");
    depthFirstTraversal(tree);
    System.out.println("breadthfirst:");
    breadthFirstTraversal(tree);
  }

  int c = 0;
  /* java depthfirst a b c d e f g h i
   * will result in: a i d g c f b e h
   * breadthfrist  : a b c d i e f g h
   * tree:  a
   *   b    c   d  i
   *   e    f   g
   */
  public void createTree(Object o) {
    System.out.println("push:"+o);
    Node n = new Node(o);
    if (tree==null) {
      System.out.println("tree:"+n); // a
      tree = n;
    } else {
      if (c<=3) {
        System.out.println("c<=3:"+n); // b  c  d
        tree.children.add(n);
      } else if (c<=6) {
        Iterator j = tree.children.iterator();
        Node m = null;
        for(int i=4; i<=c; i++) {
          System.out.println("i:"+i);
          m = (Node) j.next();
        }
        System.out.println("n:"+n);  // e  f  g
        m.children.add(n);
      } else if (c<=7) {
        Iterator j = tree.children.iterator();
        Node m4 = (Node) j.next(); // e
        j = m4.children.iterator(); 
        Node m = null;
        for(int i=7; i<=c; i++) {
          System.out.println("i:"+i);
          m = (Node) j.next();
        }
        System.out.println("n:"+n);  // h
        m.children.add(n);
      } else {
        System.out.println("else:"+n); // i
        tree.children.add(n);
      }
    }
    c++;
  }

  public String getAppletInfo() {
    return "depth first graph by Douglas A. Bauman";
  }

  static public void main(String[] args) {
    depthfirst df = new depthfirst();
    for(int i=0; i<args.length; i++) {
      df.createTree(args[i]);
    }
    df.init();
  }
}