Update README.md

Author: MonitSharma

README.md

@@ -82,6 +82,7 @@ This repository contains solutions to over 500 Leetcode problems that are organi
 | 445 | Add two numbers II | [![Medium](https://img.shields.io/badge/Medium-12100E?style=for-the-badge&logo=medium&logoColor=white)](https://medium.com/@_monitsharma/daily-leetcode-problems-problem-445-add-two-numbers-ii-170341898620) | 
 | 459 | Repeated Substring Patterns | [![Medium](https://img.shields.io/badge/Medium-12100E?style=for-the-badge&logo=medium&logoColor=white)](https://medium.com/@_monitsharma/daily-leetcode-problems-problem-459-repeated-substring-pattern-4af7f9bb0723) | 
 | 486 | Predict the Winner | [![Medium](https://img.shields.io/badge/Medium-12100E?style=for-the-badge&logo=medium&logoColor=white)](https://medium.com/@_monitsharma/daily-leetcode-problems-problem-486-predict-the-winner-cf0f5c31d718) | 
+| 501 | Find Mode in Binary Search Tree | [![Medium](https://img.shields.io/badge/Medium-12100E?style=for-the-badge&logo=medium&logoColor=white)](https://medium.com/@_monitsharma/daily-leetcode-problems-501-find-mode-in-binary-search-tree-f6ab1ba745c1) |
 | 515 | Find Largest Value in Each Tree Row | [![Medium](https://img.shields.io/badge/Medium-12100E?style=for-the-badge&logo=medium&logoColor=white)](https://medium.com/@_monitsharma/daily-leetcode-problems-515-find-largest-value-in-each-tree-row-07dbf6e23c6a) |
 | 516 | Longest Palindromic Subsequence | [![Medium](https://img.shields.io/badge/Medium-12100E?style=for-the-badge&logo=medium&logoColor=white)](https://medium.com/@_monitsharma/daily-leetcode-problems-problem-516-longest-palindromic-subsequence-a8ed158ea644) |
 | 518 |Coin Change II | [![Medium](https://img.shields.io/badge/Medium-12100E?style=for-the-badge&logo=medium&logoColor=white)](https://medium.com/@_monitsharma/daily-leetcode-problems-problem-518-coin-change-ii-a8692c17089e) |