Create Day24.cpp

Author: starwiz-7

Day24.cpp

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+/*
+    Author: Aryan Yadav
+    Construct Binary Search Tree from Preorder Traversal
+    
+    Algorithm: Traversal in tree
+    Difficulty: Medium   
+*/
+
+/**
+ * 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:
+    int i = 0;
+    TreeNode* bstFromPreorder(vector<int>& preorder,int bound = INT_MAX) {
+        if (i == preorder.size() || preorder[i] > bound) return NULL;
+        TreeNode* root = new TreeNode(preorder[i++]);
+        root->left = bstFromPreorder(preorder, root->val);
+        root->right = bstFromPreorder(preorder, bound);
+        return root;
+    }
+};