From 9fa21a5e8fab1073c4421189f5a0703ff1b653b2 Mon Sep 17 00:00:00 2001
From: doo0301 <doo0301@qq.com>
Date: Wed, 12 May 2021 19:56:58 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BC=98=E5=8C=96=200102.=E4=BA=8C=E5=8F=89?=
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---
 problems/0102.二叉树的层序遍历.md | 35 +++++++++++++++++------
 1 file changed, 27 insertions(+), 8 deletions(-)

diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md
index be2e9dca..0781e01d 100644
--- a/problems/0102.二叉树的层序遍历.md
+++ b/problems/0102.二叉树的层序遍历.md
@@ -419,18 +419,17 @@ public:
 
 Java：
 
-``` Java
-
-
+```Java
 class Solution {
     public List<List<Integer>> resList=new ArrayList<List<Integer>>();
     public List<List<Integer>> levelOrder(TreeNode root) {
-        checkFun01(root,0);
-
+        //checkFun01(root,0);
+        checkFun02(root);
+        
         return resList;
     }
 
-	//递归方式
+	//DFS--递归方式
     public void checkFun01(TreeNode node,Integer deep){
         if(node==null) return;
         deep++;
@@ -442,12 +441,33 @@ class Solution {
         }
         resList.get(deep-1).add(node.val);
         
-
         checkFun01(node.left,deep);
         checkFun01(node.right,deep);
     }
+    
+    //BFS--迭代方式--借助队列
+     public void checkFun02(TreeNode node){
+        if(node==null) return;
+        Queue<TreeNode> que=new LinkedList<TreeNode>();
+        que.offer(node);
 
+        while(!que.isEmpty()){
+            List<Integer> itemList=new ArrayList<Integer>();
+            int len=que.size();
 
+            while(len>0){
+                TreeNode tmpNode=que.poll();
+                itemList.add(tmpNode.val);
+
+                if(tmpNode.left!=null) que.offer(tmpNode.left);
+                if(tmpNode.right!=null) que.offer(tmpNode.right);
+                len--;
+            }
+            
+            resList.add(itemList);
+        }
+
+    }
 ```
 
 
@@ -458,7 +478,6 @@ Go：
 
 
 
-
 -----------------------
 * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
 * B站视频：[代码随想录](https://space.bilibili.com/525438321)