Suppose a shopkeeper of a bookstall orders for books from a vendor. Books are delivered in cartons each of which has a tag number written over it. The tag numbers are integers starting from 1 to N+1. After receiving the cartons, the shopkeeper comes to know that he has received only N cartons and he needs to identify tag number of the missing carton. Help the shopkeeper to identify which carton is missing. There may be two cases as follows: (i) cartons are not arranged in sorted order; (ii) cartons are arranged in sorted order with respect to tag numbers

Write an algorithm to solve this problem. Also mention the worst case time complexity the algorithm.