添加二叉树的广度优先和深度优先遍历算法

Author: codingWang

bin/com/duwei/designpattern/singleton/StaticInnerSingleton$HolderClass.class

@@ -1,15 +1,16 @@
 package com.duwei.designpattern.singleton;
 
 class StaticInnerSingleton {  
-    private StaticInnerSingleton() {  
-    }  
+    private StaticInnerSingleton() {}  
 
     private static class HolderClass {  
-    	//静态实例属于类，所有HolderClass对象共享一个Singleton实例，保证线程安全
+    	//静态实例属于类，所有HolderClass对象共享一个Singleton实例，
+    	//保证线程安全
         private final static StaticInnerSingleton instance = new StaticInnerSingleton();  
     }  
 
     public static StaticInnerSingleton getInstance() {  
-        return HolderClass.instance;  //初始化类时才初始化外部类对象：懒加载
+        return HolderClass.instance;  
+        //初始化类时才初始化外部类对象：懒加载
     }  
 }  

bin/com/duwei/designpattern/singleton/StaticInnerSingleton.class

@@ -1,10 +1,12 @@
 package com.duweri.interview.datastructure;
 
+import java.util.ArrayDeque;
+import java.util.Deque;
 import java.util.Stack;
 
 public class TraversalBinaryTree {
 
-	public void printNode(Node node) {
+	private void printNode(Node node) {
 		System.out.print(node.getData());
 	}
 
@@ -103,6 +105,45 @@ public void thePostOrderTraversal_Stack(Node root) {
 		}
 	}
 
+	/**
+	 * 深度优先遍历二叉树
+	 * @param root 根节点
+	 */
+	public void depthFirstSearch(Node root){
+		Stack<Node> stack = new Stack<Node>();
+		stack.push(root);
+		Node node = root;
+	    while(!stack.empty()){
+	        node = stack.pop();
+	        printNode(node);  //遍历根结点
+	        if(node.getRightNode() != null){
+	        	stack.push(node.getRightNode());  //先将右子树压栈
+	        }
+	        if(node.getLeftNode() != null){
+	        	stack.push(node.getLeftNode());  //再将左子树压栈
+	        }
+	    }
+	}
+	/**
+	 * 广度优先遍历二叉树
+	 * @param node 根节点
+	 */
+	public void breadthFirst(Node node) {
+	    Deque<Node> nodeDeque = new ArrayDeque();
+	    nodeDeque.add(node);
+	    while (!nodeDeque.isEmpty()) {
+	        node = nodeDeque.peekFirst();
+	        printNode(node);
+	        if (node.getLeftNode()!=null) {
+	        	nodeDeque.add(node.getLeftNode());
+			}
+	        if (node.getRightNode()!=null) {
+				nodeDeque.add(node.getRightNode());
+			}
+	    }
+	}
+	
+	
 	public static void main(String[] args) {
 		TraversalBinaryTree tree = new TraversalBinaryTree();
 		Node root = tree.init();

bin/com/duweri/interview/datastructure/TraversalBinaryTree$Node.class

@@ -0,0 +1,32 @@
+package com.offer;
+
+import java.util.Scanner;
+
+/**
+ * 青蛙跳台阶问题：求斐波那契数列
+ * <有一楼梯共m级，刚开始时你在第一级，>
+ * <若每次只能跨上一级或二级，要走上第m级，>
+ * <共有多少走法？>
+ * @author 杜伟
+ */
+
+public class JumpStep {
+	public static void main(String[] args) {
+		Scanner sc = new Scanner(System.in);
+		JumpStep m = new JumpStep();
+		while(sc.hasNext()) {
+			int num = sc.nextInt();
+			for(int i=0; i<num; i++) {
+				System.out.println(m.Fan(sc.nextInt()));
+			}
+		}
+	
+	}
+	public int Fan(int n) {
+		if(n == 1) return 0;
+		if(n == 2) return 1;
+		if(n == 3) return 2;
+		return Fan(n-1)+Fan(n-2);
+	}
+}
+