剑指

Author: legolas007

Solution55.java

@@ -18,9 +18,11 @@ public class Solution55 {
     public int TreeDepth(TreeNode root){
         if (root == null)
             return 0;
+
         Queue<TreeNode> queue = new LinkedList<>();
         queue.offer(root);
         int max_depth = 0;
+
         while (!queue.isEmpty()){
             int size = queue.size();
             for (int i = 0;i < queue.size();i++){
@@ -34,6 +36,7 @@ public int TreeDepth(TreeNode root){
             }
             ++max_depth;
         }
+
         return max_depth;
         //return Math.max(TreeDepth(root.left),TreeDepth(root.right))+1;//递归
     }

Solution55_2.java

@@ -1,12 +1,32 @@
 package com.usher.algorithm.offer;
 
+import java.util.LinkedList;
+import java.util.Queue;
+
 /**
  * @Author: Usher
  * @Description:
  * 平衡二叉树
+ * 后序遍历，在遍历左右子树节点的时候记录他的深度
  */
 public class Solution55_2 {
+
+    private boolean flag = true;
     public boolean IsBalanced_Solution(TreeNode root) {
+        TreeDepth(root);
+        return flag;
+    }
 
+    private int TreeDepth(TreeNode root){
+        if (root == null)
+            return 0;
+
+        int left = TreeDepth(root.left);
+        int right = TreeDepth(root.right);
+
+        if (Math.abs(left - right) > 1)
+            flag = false;
+        return Math.max(left,right)+1;//递归
     }
+
 }

Solution58_1.java

@@ -1,5 +1,8 @@
 package com.usher.algorithm.offer;
 
+import java.util.LinkedList;
+import java.util.Queue;
+
 /**
  * @Author: Usher
  * @Description: