Merge pull request gzc426#15 from V1ncentzzZ/V1ncentzzZ-patch-12

V1ncentzzZ · web-flow · commit f73b757a47f2 · 2018-12-07T14:44:08.000+08:00
104. 二叉树的最大深度打卡
diff --git a/2018.12.07-leetcode104/。V1ncentzzZ.md b/2018.12.07-leetcode104/。V1ncentzzZ.md
@@ -0,0 +1,51 @@
+[104. 二叉树的最大深度][https://leetcode-cn.com/problems/maximum-depth-of-binary-tree/]
+
+给定一个二叉树，找出其最大深度。
+
+二叉树的深度为根节点到最远叶子节点的最长路径上的节点数。
+
+说明: 叶子节点是指没有子节点的节点。
+
+示例：
+给定二叉树 [3,9,20,null,null,15,7]，
+```
+   3
+   / \
+  9  20
+    /  \
+   15   7
+```
+返回它的最大深度 3 。
+
+```
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode(int x) { val = x; }
+ * }
+ */
+class Solution {
+//     public int maxDepth(TreeNode root) {
+//         if(root == null) return 0;
+//         return getDepth(root.left,root.right,1);
+//     }
+    
+//     public int getDepth(TreeNode node1,TreeNode node2,int high){
+//         if(node1 == null && node2 == null) return high;
+//         high++;
+//         if(node1 == null) return getDepth(node2.left,node2.right,high);
+//         if(node2 == null) return getDepth(node1.left,node1.right,high);
+//         return Math.max(getDepth(node1.left,node1.right,high),getDepth(node2.left,node2.right,high));
+//     }
+    
+    public int maxDepth(TreeNode root) {
+        if(root == null) return 0;
+        int left = maxDepth(root.left);
+        int right = maxDepth(root.right);
+        return 1 + (left > right ? left : right);
+    }
+}
+```
