From 4ae4ce2bcfce05e4b91f24322bbdcdcb1d9c9e2e Mon Sep 17 00:00:00 2001
From: Joshua <47053655+Joshua-Lu@users.noreply.github.com>
Date: Fri, 14 May 2021 01:15:06 +0800
Subject: [PATCH] =?UTF-8?q?Update=200104.=E4=BA=8C=E5=8F=89=E6=A0=91?=
 =?UTF-8?q?=E7=9A=84=E6=9C=80=E5=A4=A7=E6=B7=B1=E5=BA=A6.md?=
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添加 0104.二叉树的最大深度 Java版本
---
 problems/0104.二叉树的最大深度.md | 44 +++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/problems/0104.二叉树的最大深度.md b/problems/0104.二叉树的最大深度.md
index 814beb55..0d3cd693 100644
--- a/problems/0104.二叉树的最大深度.md
+++ b/problems/0104.二叉树的最大深度.md
@@ -231,7 +231,51 @@ public:
 
 
 Java：
+```Java
+class Solution {
+    /**
+     * 递归法
+     */
+    public int maxDepth(TreeNode root) {
+        if (root == null) {
+            return 0;
+        }
+        int leftDepth = maxDepth(root.left);
+        int rightDepth = maxDepth(root.right);
+        return Math.max(leftDepth, rightDepth) + 1;
+    }
+}
+```
 
+```Java
+class Solution {
+    /**
+     * 迭代法，使用层序遍历
+     */
+    public int maxDepth(TreeNode root) {
+        if(root == null) {
+            return 0;
+        }
+        Deque<TreeNode> deque = new LinkedList<>();
+        deque.offer(root);
+        int depth = 0;
+        while (!deque.isEmpty()) {
+            int size = deque.size();
+            depth++;
+            for (int i = 0; i < size; i++) {
+                TreeNode poll = deque.poll();
+                if (poll.left != null) {
+                    deque.offer(poll.left);
+                }
+                if (poll.right != null) {
+                    deque.offer(poll.right);
+                }
+            }
+        }
+        return depth;
+    }
+}
+```
 
 Python：