linked list
- https://www.codewithharry.com/videos/data-structures-and-algorithms-in-hindi-14/
- https://www.codewithharry.com/videos/data-structures-and-algorithms-in-hindi-15/
- https://www.codewithharry.com/videos/data-structures-and-algorithms-in-hindi-30/
- https://www.codewithharry.com/videos/data-structures-and-algorithms-in-hindi-38/
- https://www.codewithharry.com/videos/data-structures-and-algorithms-in-hindi-39/
- https://www.codewithharry.com/videos/data-structures-and-algorithms-in-hindi-42/
- https://www.programiz.com/dsa/circular-queue