Prime days

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COSC 326

2019 Semester 2

?tude 2

Prime days

Obviously, a day is prime if the day of the month is prime - in our calendar that would mean one of 2, 3, 5, 7, 11, 13, 17, 19, 23, 29 or 31 (the latter two only being possible in some months). A day is really prime if it is prime and occurs in a prime-numbered month (i.e., February, March, May, July or November). Finally, a day is truly prime if it is really prime and it is a prime-numbered day of the year. For example February 2 is really prime but not truly prime because it is the 33rd day of the year and 33 is not prime. In a non leap-year March 2 is truly prime because it's the 61st day of the year.

Problem Statement

In preparation for the launch of a universal calendar app (suitable for use on all planets and in all solar systems) you have been asked to develop a program that computes all the truly prime days of a year given only the lengths of the months. You may assume that the length of a year is never greater than 2 billion days.


Write a program that takes input from the command line a single sequence of month lengths (always positive integers) separated by spaces and prints to stdout all the truly prime days of the corresponding calendar, one per line in the following format:


For instance if you submitted a java program called App in a package called calendar then the following input:

> java calendar.App 5 5 10

would produce the output:

7: 2 2 13: 3 3 17: 3 7

(1 point, Individual)

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