add folder & cpp(0ms) version

Author: zouwx2cs

solution/0965.Univalued Binary Tree/Solution.cpp

@@ -0,0 +1,30 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+ * };
+ */
+class Solution {
+private:
+    bool isUnivalVal(TreeNode* r, int val)
+    {
+        if (val != r->val)
+            return false ;
+        
+        if (r->left && !isUnivalVal(r->left, val))
+            return false ;
+        if (r->right && !isUnivalVal(r->right, val))
+            return false ;
+        
+        return true ;
+    }
+public:
+    bool isUnivalTree(TreeNode* root) {
+        if (nullptr == root)
+            return true ;
+        return isUnivalVal(root, root->val) ;
+    }
+} ;