added Validate Binary Search Tree problem

arunsprasad · Nov 25, 2022 · 6c2a2dd · 6c2a2dd
1 parent a85f2f5
commit 6c2a2dd
Showing 1 changed file with 32 additions and 0 deletions.
diff --git a/Binary Search Tree/Validate Binary Search Tree.cpp b/Binary Search Tree/Validate Binary Search Tree.cpp
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+/**
+ * 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:
+    void inorder(TreeNode *root, long long  &prevValue, bool &flag){
+        if(root){
+            inorder(root->left, prevValue, flag);
+            if(prevValue>=(root->val)){
+                flag = false;
+            }
+            prevValue = (root->val);
+            inorder(root->right, prevValue, flag);
+        }
+    }
+    bool isValidBST(TreeNode* root) {
+        bool flag = true;
+        long long prevValue = LONG_MIN;
+        inorder(root, prevValue, flag);
+
+        return flag;
+
+    }
+};