From 4bf1ce28e6a74e5957b2504ecfd5cf89cfe4e353 Mon Sep 17 00:00:00 2001
From: Sindhu  Inti <89198083+Sindhuinti@users.noreply.github.com>
Date: Sun, 9 Oct 2022 13:40:51 +0530
Subject: [PATCH] feat: leetcode Construct Binary Search Tree from Preorder
 Traversal solution (1008)

---
 leetcode/README.md  |  1 +
 leetcode/src/1008.c | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)
 create mode 100644 leetcode/src/1008.c

diff --git a/leetcode/README.md b/leetcode/README.md
index b20037394d..456201b9f8 100644
--- a/leetcode/README.md
+++ b/leetcode/README.md
@@ -89,6 +89,7 @@ LeetCode
 |938|[Range Sum of BST](https://leetcode.com/problems/range-sum-of-bst/) | [C](./src/938.c)|Easy|
 |965|[Univalued Binary Tree](https://leetcode.com/problems/univalued-binary-tree/) | [C](./src/965.c)|Easy|
 |977|[Squares of a Sorted Array](https://leetcode.com/problems/squares-of-a-sorted-array/) | [C](./src/977.c)|Easy|
+|1008|[Construct Binary Search Tree from Preorder Traversal](https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal/description/) | [C](./src/1008.c)|Medium|
 |1089|[Duplicate Zeros](https://leetcode.com/problems/duplicate-zeros/) | [C](./src/1089.c)|Easy|
 |1184|[Distance Between Bus Stops](https://leetcode.com/problems/distance-between-bus-stops/) | [C](./src/1184.c)|Easy|
 |1189|[Maximum Number of Balloons](https://leetcode.com/problems/maximum-number-of-balloons/) | [C](./src/1189.c)|Easy|
diff --git a/leetcode/src/1008.c b/leetcode/src/1008.c
new file mode 100644
index 0000000000..ce4871ecd4
--- /dev/null
+++ b/leetcode/src/1008.c
@@ -0,0 +1,39 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     struct TreeNode *left;
+ *     struct TreeNode *right;
+ * };
+ */
+
+struct TreeNode* bstFromPreorder(int* preorder, int preorderSize)
+{
+    struct TreeNode* new;
+    int left_ptr;
+
+    new = malloc(sizeof(struct TreeNode));
+    new->val = preorder[0];
+
+    if (preorderSize == 1)
+    {
+        new->right = NULL;
+        new->left = NULL;
+        return new;
+    }
+
+    left_ptr = 1;
+    while ((left_ptr < preorderSize) && (preorder[left_ptr] < preorder[0]))
+        left_ptr++;
+    if (left_ptr == 1)
+        new->left = NULL;
+    else
+        new->left = bstFromPreorder(preorder + 1, left_ptr - 1);
+    if (left_ptr < preorderSize)
+        new->right =
+            bstFromPreorder(preorder + left_ptr, preorderSize - left_ptr);
+    else
+        new->right = NULL;
+
+    return new;
+}