Merge pull request #1068 from NAVJOT-786/main

added leetcode solution for problem 108

Author: ajay-dhangar

dsa-solutions/lc-solutions/0100-0199/0108-convert-sorted-array-to-binary-search-tree.md

@@ -0,0 +1,113 @@
+---
+id: convert-sorted-array-to-binary-search-tree
+title: Convert Sorted Array to Binary Search Tree
+sidebar_label: 0108-convert-sorted-array-to-binary-search-tree
+tags:
+  - Array
+  - Binary search tree
+  - Divide and Conquer
+  - Tree
+  - Binary Tree
+description: "Given an integer array nums where the elements are sorted in ascending order, convert it to a height-balanced binary search tree."
+---
+
+
+### Problem Description
+
+Given an integer array nums where the elements are sorted in ascending order, convert it to a height-balanced binary search tree.
+ 
+### Examples
+
+#### Example 1
+
+- **Input:** ` nums = [-10,-3,0,5,9]`
+- **Output:** `[0,-3,9,-10,null,5]`
+
+#### Example 2
+
+- **Input:** ` nums = [1,3]`
+- **Output:** `[3,1]`
+
+### Constraints
+
+- $1 \leq \text{nums.length} \leq 10^4$
+- $-10^4 \leq \text{nums}[i] \leq 10^4$
+- nums is sorted in a strictly increasing order
+
+### Solution Code
+
+#### Python
+
+```python
+class Solution:
+    def sortedArrayToBST(self, nums: List[int]) -> Optional[TreeNode]:
+        total_nums = len(nums)
+        if not total_nums:
+            return None
+
+        mid_node = total_nums // 2
+        return TreeNode(
+            nums[mid_node], 
+            self.sortedArrayToBST(nums[:mid_node]), self.sortedArrayToBST(nums[mid_node + 1 :])
+        )
+```
+
+#### Java
+
+```java
+class Solution {
+    public TreeNode sortedArrayToBST(int[] nums) {
+        int n=nums.length;
+        if (n ==0) return null;
+        if (n ==1) {
+            TreeNode head = new TreeNode(nums[0]);
+            return head;
+        }
+
+        TreeNode head = buildBST(nums,0,n-1);
+        return head;
+    }
+    private TreeNode buildBST (int [] nums, int low, int high){
+        if(low>high) return null;
+
+        int mid =low+(high-low)/2;
+        TreeNode node = new TreeNode(nums[mid]);
+        node.left =buildBST(nums,low,mid-1);
+        node.right =buildBST(nums,mid+1,high);
+        return node;
+    }
+}
+```
+
+#### C++
+
+```cpp
+class Solution {
+public:
+    TreeNode* sortedArrayToBST(vector<int>& nums) {
+        return constructBSTRecursive(nums, 0, nums.size() - 1);
+    }
+
+    TreeNode* constructBSTRecursive(vector<int>& nums, int left, int right) {
+        if(left > right)
+            return NULL;
+        int mid = left + (right - left) / 2;
+        TreeNode* node = new TreeNode(nums[mid]);
+        node->left = constructBSTRecursive(nums, left, mid - 1);
+        node->right = constructBSTRecursive(nums, mid + 1, right);
+        return node;
+    }
+};
+```
+#### Javascript
+
+```javascript
+var sortedArrayToBST = function(nums) {
+    if(!nums.length) return null;
+    let mid = Math.floor(nums.length / 2);
+    let root = new TreeNode(nums[mid]);
+    root.left = sortedArrayToBST(nums.slice(0, mid));
+    root.right = sortedArrayToBST(nums.slice(mid + 1));
+    return root;
+};
+```