Create 110. Balanced Binary Tree

Author: haibarawu

110. Balanced Binary Tree

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+/****
+Given a binary tree, determine if it is height-balanced.
+For this problem, a height-balanced binary tree is defined as a binary tree, 
+in which the depth of the two subtrees of every node never differ by more than 1.
+****/
+
+//Java solution:
+
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode(int x) { val = x; }
+ * }
+ */
+public class Solution {
+    public int depth(TreeNode node){
+        if(node == null){
+            return 0;
+        }
+        else if(node.left == null && node.right == null){
+            return 1;
+        }
+        else{
+            int left = depth(node.left);
+            int right = depth(node.right);
+            return Math.max(left, right) + 1;
+        }
+    }
+    
+    public boolean isBalanced(TreeNode root) {
+        if(root == null){
+            return true;
+        }
+        int left = depth(root.left);
+        int right = depth(root.right);
+        
+        if(Math.abs(left - right) > 1){
+            return false;
+        }
+        return isBalanced(root.left) && isBalanced(root.right);
+    }
+}