如何遍历这个树啊

Question

这棵树有左孩子，右孩子，然后左孩子还有左孩子，右孩子，等，是一颗二叉树
classs Node
{
  Node left(){};  Node right(){};  String nodeName;
}现在有1个方法 void  printTree(Node root)
{
  //todo   //传入是根节点，如何把所有节点的nodename打印出来，谢谢了
}

Answer 1

void  printTree(Node root)
{
      if(root.left()!=null)
           printTree(root.left());
      if(root.right()!=null)
           printTree(root.right());
      System.out.printf(root.nodeName)
  
}

Answer 2

http://tech.ddvip.com/2008-12/122847009897802.html

Answer 3

贴二叉树递归非递归前中后序遍历代码
供参考
public void preOrder(BinTreeNode<T>node){
if(node == null){
return;
}
printInfo(node);
if(node.getLeftNode()!=null){
preOrder(node.getLeftNode());
}
if(node.getRightNode()!=null){
preOrder(node.getRightNode());
}
}
public void iteraPreOrder(BinTreeNode<T>node){
Stack<BinTreeNode<T>> stack = new Stack<BinTreeNode<T>>();
if(node != null){
stack.push(node);
while(!stack.empty()){
node = stack.pop();
printInfo(node);
if(node.getLeftNode()!=null){
stack.push(node.getRightNode());
}
if(node.getRightNode()!=null){
stack.push(node.getLeftNode());
}
}
}
}
public void midOrder(BinTreeNode<T>node){
if(node == null){
return;
}
if(node.getLeftNode()!=null){
midOrder(node.getLeftNode());
}
printInfo(node);
if(node.getRightNode()!=null){
midOrder(node.getRightNode());
}
}
public void iteraMidOrder(BinTreeNode<T>p){
Stack<BinTreeNode<T>>stack = new Stack<BinTreeNode<T>>();
BinTreeNode<T> node = p;
while(node != null || stack.size()>0){
while(node != null){
stack.push(node);
node = node.getLeftNode();
}
if(stack.size()>0){
node = stack.pop();
printInfo(node);
node = node.getRightNode();
}
}
}
public void lastOrder(BinTreeNode<T>node){
if(node == null){
return;
}
if(node.getLeftNode()!=null){
lastOrder(node.getLeftNode());
}
if(node.getRightNode()!=null){
lastOrder(node.getRightNode());
}
printInfo(node);
}
public void iteraLastOrder(BinTreeNode<T>p){
BinTreeNode<T> q = p;   
        Stack<BinTreeNode<T>> stack = new Stack<BinTreeNode<T>>();   
        while (p != null) {   
            // 左子树入栈   
            for (; p.getLeftNode() != null; p = p.getLeftNode())   
                stack.push(p);   
            // 当前节点无右子或右子已经输出   
            while (p != null && (p.getRightNode() == null || p.getRightNode() == q)) {   
                printInfo(p);   
                q = p;// 记录上一个已输出节点   
                if (stack.empty())   
                    return;   
                p = stack.pop();   
            }   
            // 处理右子   
            stack.push(p);   
            p = p.getRightNode();   
        }  
}
public void levOrder(BinTreeNode<T>node){
ArrayList<BinTreeNode<T>> tempList = new ArrayList<BinTreeNode<T>>();
tempList.add(node);
while(tempList.size()!=0){
BinTreeNode<T> nodeIndex0 = tempList.get(0);
if(nodeIndex0.getLeftNode()!=null){
tempList.add(nodeIndex0.getLeftNode());
}
if(nodeIndex0.getRightNode()!=null){
tempList.add(nodeIndex0.getRightNode());
}
printInfo(nodeIndex0);
tempList.remove(0);
}
tempList = null;
}
public void printInfo(BinTreeNode<T> node){
System.out.print(node.getValue().toString()+"  ");
}