Java实现二叉树的递归与非递归遍历
时间:2011-04-13 zhangjunhd
构造树如下:
其中二叉树节点类
/** 二叉树节点 */
public class BTNode {
private char key;
private BTNode left, right;
public BTNode(char key) {
this(key, null, null);
}
public BTNode(char key, BTNode left, BTNode right) {
this.key = key;
this.left = left;
this.right = right;
}
public char getKey() {
return key;
}
public void setKey(char key) {
this.key = key;
}
public BTNode getLeft() {
return left;
}
public void setLeft(BTNode left) {
this.left = left;
}
public BTNode getRight() {
return right;
}
public void setRight(BTNode right) {
this.right = right;
}
}
Java实现二叉树的递归与非递归遍历(2)
时间:2011-04-13 zhangjunhd
遍历二叉树
/** 二叉树遍历 */
public class BinTree {
protected BTNode root;
public BinTree(BTNode root) {
this.root = root;
}
public BTNode getRoot() {
return root;
}
/** 构造树 */
public static BTNode init() {
BTNode a = new BTNode(''A'');
BTNode b = new BTNode(''B'', null, a);
BTNode c = new BTNode(''C'');
BTNode d = new BTNode(''D'', b, c);
BTNode e = new BTNode(''E'');
BTNode f = new BTNode(''F'', e, null);
BTNode g = new BTNode(''G'', null, f);
BTNode h = new BTNode(''H'', d, g);
return h;// root
}
/** 访问节点 */
public static void visit(BTNode p) {
System.out.print(p.getKey() + " ");
}
/** 递归实现前序遍历 */
protected static void preorder(BTNode p) {
if (p != null) {
visit(p);
preorder(p.getLeft());
preorder(p.getRight());
}
}
/** 递归实现中序遍历 */
protected static void inorder(BTNode p) {
if (p != null) {
inorder(p.getLeft());
visit(p);
inorder(p.getRight());
}
}
/** 递归实现后序遍历 */
protected static void postorder(BTNode p) {
if (p != null) {
postorder(p.getLeft());
postorder(p.getRight());
visit(p);
}
}
/** 非递归实现前序遍历 */
protected static void iterativePreorder(BTNode p) {
Stack<BTNode> stack = new Stack<BTNode>();
if (p != null) {
stack.push(p);
while (!stack.empty()) {
p = stack.pop();
visit(p);
if (p.getRight() != null)
stack.push(p.getRight());
if (p.getLeft() != null)
stack.push(p.getLeft());
}
}
}
/** 非递归实现后序遍历 */
protected static void iterativePostorder(BTNode p) {
BTNode q = p;
Stack<BTNode> stack = new Stack<BTNod
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