Convert Sorted List to Binary Search Tree LeetCode Programming Solutions | LeetCode Problem Solutions in C++, Java, & Python [💯Correct]

LeetCode Problem | LeetCode Problems For Beginners | LeetCode Problems & Solutions | Improve Problem Solving Skills | LeetCode Problems Java | LeetCode Solutions in C++

Hello Programmers/Coders, Today we are going to share solutions to the Programming problems of LeetCode Solutions in C++, Java, & Python. At Each Problem with Successful submission with all Test Cases Passed, you will get a score or marks and LeetCode Coins. And after solving maximum problems, you will be getting stars. This will highlight your profile to the recruiters.

In this post, you will find the solution for the Convert Sorted List to Binary Search Tree in C++, Java & Python-LeetCode problem. We are providing the correct and tested solutions to coding problems present on LeetCode. If you are not able to solve any problem, then you can take help from our Blog/website.

Use “Ctrl+F” To Find Any Questions Answer. & For Mobile User, You Just Need To Click On Three dots In Your Browser & You Will Get A “Find” Option There. Use These Option to Get Any Random Questions Answer.

About LeetCode

LeetCode is one of the most well-known online judge platforms to help you enhance your skills, expand your knowledge and prepare for technical interviews. 

LeetCode is for software engineers who are looking to practice technical questions and advance their skills. Mastering the questions in each level on LeetCode is a good way to prepare for technical interviews and keep your skills sharp. They also have a repository of solutions with the reasoning behind each step.

LeetCode has over 1,900 questions for you to practice, covering many different programming concepts. Every coding problem has a classification of either Easy, Medium, or Hard.

LeetCode problems focus on algorithms and data structures. Here is some topic you can find problems on LeetCode:

• Mathematics/Basic Logical Based Questions
• Arrays
• Strings
• Hash Table
• Dynamic Programming
• Stack & Queue
• Trees & Graphs
• Greedy Algorithms
• Breadth-First Search
• Depth-First Search
• Sorting & Searching
• BST (Binary Search Tree)
• Database
• Linked List
• Recursion, etc.

Leetcode has a huge number of test cases and questions from interviews too like Google, Amazon, Microsoft, Facebook, Adobe, Oracle, Linkedin, Goldman Sachs, etc. LeetCode helps you in getting a job in Top MNCs. To crack FAANG Companies, LeetCode problems can help you in building your logic.

Link for the Problem – Convert Sorted List to Binary Search Tree– LeetCode Problem

Convert Sorted List to Binary Search Tree– LeetCode Problem

Problem:

Given the head of a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST.

For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1.

Example 1:

Input: head = [-10,-3,0,5,9]
Output: [0,-3,9,-10,null,5]
Explanation: One possible answer is [0,-3,9,-10,null,5], which represents the shown height balanced BST.

Example 2:

Input: head = []
Output: []

Constraints:

• The number of nodes in head is in the range [0, 2 * 104].
• -105 <= Node.val <= 105

Convert Sorted List to Binary Search Tree– LeetCode Solutions

Convert Sorted List to Binary Search Tree Solution in C++:

class Solution {
 public:
  TreeNode* sortedListToBST(ListNode* head) {
    vector<int> A;

    // construct the array
    for (ListNode* curr = head; curr; curr = curr->next)
      A.push_back(curr->val);

    return helper(A, 0, A.size() - 1);
  }

 private:
  TreeNode* helper(const vector<int>& A, int l, int r) {
    if (l > r)
      return nullptr;

    const int m = l + (r - l) / 2;
    TreeNode* root = new TreeNode(A[m]);
    root->left = helper(A, l, m - 1);
    root->right = helper(A, m + 1, r);

    return root;
  }
};

Convert Sorted List to Binary Search Tree Solution in Java:

class Solution {
  public TreeNode sortedListToBST(ListNode head) {
    List<Integer> A = new ArrayList<>();

    // construct the array
    for (ListNode curr = head; curr != null; curr = curr.next)
      A.add(curr.val);

    return helper(A, 0, A.size() - 1);
  }

  private TreeNode helper(List<Integer> A, int l, int r) {
    if (l > r)
      return null;

    final int m = l + (r - l) / 2;
    TreeNode root = new TreeNode(A.get(m));
    root.left = helper(A, l, m - 1);
    root.right = helper(A, m + 1, r);

    return root;
  }
}

Convert Sorted List to Binary Search Tree Solution in Python:

class Solution:
  def sortedListToBST(self, head: ListNode) -> TreeNode:
    def findMid(head: ListNode) -> ListNode:
      prev = None
      slow = head
      fast = head

      while fast and fast.next:
        prev = slow
        slow = slow.next
        fast = fast.next.next
      prev.next = None

      return slow

    if not head:
      return None
    if not head.next:
      return TreeNode(head.val)

    mid = findMid(head)
    root = TreeNode(mid.val)
    root.left = self.sortedListToBST(head)
    root.right = self.sortedListToBST(mid.next)

    return root