CSci 3501 Algorithms and Computability - Lab 12.

Due Monday, November 15th at 11:59pm

What to submit and when:

• All submissions are electronic: by e-mail to elenam at morris.umn.edu and CC to all lab partners. Please do not delete your e-mail from "Sent mail" or your mailbox until the end of the semester.
• When working on the lab, please comment your work so that it is clear what contributions of each person are.
• At the end of the lab each group should send me the results of their in-class work. Please indicate if this is your final submission.
• If your submission at the end of the lab time was not final, please send me(CC to the lab partner(s)) a final copy before the due time. Please use the subject "3501 Lab N", where N is the lab number.

Lab assignment

For the first part work in groups as assigned. For the second part work in pairs.

Lab overview and goals

The goals of the lab are: to get experience with algorithmic problem-solving; to get practice with the pumping lemma for context-free languages.

Problem-solving, part 1 (20 points)

For this lab you will be working on a problem defined here. Please log in with your dungeon user name and password. Groups are assigned. The problem statement is in Help/Documentation.

You should download a Desktop application for testing (also in Help/Documentation).

Problem submissions generate scores for a given set of test cases. You can also generate random test cases or define your own via the Desktop application.

Your goal for this lab is to get familiar with the problem and the software. Every group should submit at least one copy of the code at the end of the lab. Please don't submit more than three. Your solution at the end of the lab will probably not be very good, that's OK.

Next time (Thursday) you will get a chance to fine-tune your algorithm. On Monday you will submit "round 1" solution. There will be the next round that will allow you to improve your solution. Only the results of the final round will be counted for competition and extra credit.

Play the context-free "pumping lemma game" (7 points, for Thursday lab (not for Wednesday!))

Use the tutorial for the pumping lemma. Play the "pumping lemma game" for the following examples. For each example state whether the language is context-free; justify it based on which side has a winning strategy in the pumping lemma game.

• The third language (a^n b^j a^n b^j, n >= 0, j >= 0) -- computer goes first.
• The eighth language (a^k b^n c^n d^j: j not equal to k) -- you go first

What to submit

• Submit your JFLAP files as attachments, CC your group. Make sure to submit your automata files (as .jff) and your input data (as .txt). Make sure to follow the naming requirements! Make it clear which data refers to which automaton.

CSci 3501 course web site.