Create main.cpp

Author: JawadSher

18 - Binary Search Tree Data Structure Problems/03 - Validate Binary Search Tree/main.cpp

@@ -0,0 +1,29 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
+ * };
+ */
+class Solution {
+public:
+    bool isBST(TreeNode* root, long min, long max){
+        if(root == NULL) return true;
+
+        if(root -> val > min && root -> val < max){
+            bool left = isBST(root -> left, min, root -> val);
+            bool right = isBST(root -> right, root -> val, max);
+
+            return left && right;
+        }else{
+            return false;
+        }
+    }
+    bool isValidBST(TreeNode* root) {
+        return isBST(root, LONG_MIN, LONG_MAX);
+    }
+};