Time: 8 ms (94.19%), Space: 21.6 MB (85.86%) - LeetHub

Author: JanaSabuj

validate-binary-search-tree/validate-binary-search-tree.cpp

@@ -0,0 +1,19 @@
+/**
+ * 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 isValidBST(TreeNode* root, long minval = LLONG_MIN, long maxval = LLONG_MAX) {
+        if(root == NULL)
+            return true;
+        return isValidBST(root->left, minval, root->val) and (minval < root->val and root->val < maxval) and isValidBST(root->right, root->val, maxval);
+    }
+};