Create 965. Univalued Binary Tree

Author: haibarawu

965. Univalued Binary Tree

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+/*
+// A binary tree is univalued if every node in the tree has the same value.
+// Return true if and only if the given tree is univalued.
+
+Example 1:
+Input: [1,1,1,1,1,null,1]
+Output: true
+
+Example 2:
+Input: [2,2,2,5,2]
+Output: false
+*/
+
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode(int x) { val = x; }
+ * }
+ */
+class Solution {
+    public boolean isUnivalTree(TreeNode root) {
+        boolean left_correct = (root.left == null ||
+                (root.val == root.left.val && isUnivalTree(root.left)));
+        
+        boolean right_correct = (root.right == null ||
+                (root.val == root.right.val && isUnivalTree(root.right)));
+        
+        return left_correct && right_correct;
+    }
+}