Modify the program from Lab 7 that displays shelter population over time to: ask the user to specify the input file, ask the user to specify the output file, make a plot of the fraction of the total population that are single over time from the data in input file, and store the plot in the output file the user specified.

Write a method named addall that could be placed inside the hashintset class. this method accepts another hashintset as a parameter and adds all elements from that set into the current set, if they are not already present. for example, if a set s1 contains [1, 2, 3] and another set s2 contains [1, 7, 3, 9], the call of s1.addall(s2); would change s1 to store [1, 2, 3, 7, 9] in some order. you are allowed to call methods on your set and/or the other set. do not modify the set passed in. this method should run in o(n) time where n is the number of elements in the parameter set passed in.

Jason works as an accountant in a department store. he needs to keep a daily record of all the invoices issued by the store. which file naming convention would him the most?

Which feature is selected to practice and save the timing of a presentation