109. Convert Sorted List to Binary Search Tree

Author: amitbansal7

convert-sorted-list-to-binary-search-tree.cpp

@@ -0,0 +1,40 @@
+//Runtime: 22 ms
+class Solution {
+public:
+
+    TreeNode* insert(TreeNode* root, int val)
+    {
+        if(!root)
+            return new TreeNode(val);
+        else if(root->val < val)
+            return root->right = insert(root->right, val);
+        else
+            return root->left = insert(root->left, val);
+    }
+
+    TreeNode* MakeBST(TreeNode* root, int l,int h, vector<int> &nums)
+    {
+        if(l>h)
+            return NULL;
+
+        int mid = (l+h)/2;
+        root = insert(root, nums[mid]);
+
+        root->right = MakeBST(root, mid+1, h, nums);
+        root->left = MakeBST(root, l, mid-1, nums);
+
+        return root;
+
+    }
+    TreeNode* sortedListToBST(ListNode* head) {
+        vector<int> nums;
+
+        while(head!=NULL)
+        {
+            nums.push_back(head->val);
+            head = head->next;
+        }
+
+        return MakeBST(NULL, 0, nums.size()-1, nums);
+    }
+};