1 Problem 1 : Consecutive Numbers (https://leetcode.com/problems/consecutive-numbers/)
2 Problem 2 :Number of Passengers in Each Bus ( https://leetcode.com/problems/the-number-of-passengers-in-each-bus-i/ )
3 Problem 3 :User Activity (https://leetcode.com/problems/user-activity-for-the-past-30-days-i/ )
4 Problem 4 :Dynamic Pivoting of a Table ( https://leetcode.com/problems/dynamic-pivoting-of-a-table/ )