1. The rewrite of paper #1 is now due at 5:00pm on Friday, May 6.
2. The first version of paper #2 is due at 11:59pm on Sunday, May 8.

1. Copyright reform
2. Software patent reform

• If both players cooperate, the score is -1 for each player
• If both players defect, the score is -5 for each player
• If one player cooperates and the other defects, the defector scores 0 and the unfortunate cooperator scores -10.

Your job is to implement a class named PDStrategy that uses the historical actions of your opponent to decide whether to cooperate or defect. You can implement this class in either C++ or Java. Click on the language you prefer to download the starter files.

Entries are due by 11:59pm on Sunday and should be mailed to eroberts@cs.stanford.edu. After receiving the entries, we will run every entry against every other entry and record the total score. (Note that the payoff matrix used in class means that all players will end up with a negative score; you want your algorithm to run up the least negative total.)

Every entry that compiles and runs correctly (and that does something more intelligent than simply returning "COOPERATE" or "DEFECT" every time) will get one extra-credit point. The winner of the round-robin tournament will get a total of three points; the runner-up will receive a total of two.

1. There are no late days on the major papers.
2. All extension requests must be directed to Shrey Gupta, the TA who has been designated as the extensions czar.
3. Those of you whose papers are being reviewed by TWP must sign up for a tutorial as described on the web site.
4. All papers should be sent by e-mail to your TA. PDF format is best.
5. The camera-ready version is optional. In past years, many students have wanted to submit one.
6. Students in 181W must submit rewrites. Students in 181 may submit rewrites on the same schedule. The original counts for 25% of the grade and the rewrite for 75%.

• Fred Brooks, No Silver Bullet
• Leveson/Turner on the Therac-25
• Public-domain materials from Part 4