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SRM 93
May 30, 2002

Room 1 Review
Coding Phase

The Coding Phase begain as usual, with everybody starting on the Level 1 problem except for dmwright, who began with his regular strategy of starting on the Level 2 problem. doeth, John Dehtridge, and reid did not start until over five minutes into the contest.

Twenty seconds after reid opened the Level 1 problem, SnapDragon made the first submission, for 286.08 points. ZorbaTHut followed close behind with 281.42 points Next in line for Level 1 submissions were (in order of scores rather than chronology): John Dethridge (283.46 points); malpt; doeth; venco; and ambrose. At this point in time, this left dmwright and reid without any submissions yet.

SnapDragon also made the first submission of the Level 2 problem, submitting his solution at the 18 minute mark for 437.76 points. This was shortly followed by reid's relatively poor showing of 252.74 points for the Level 1 problem. Next in line for Level 2 submissions were (in order of score again): malpt; reid; ambrose; doeth; John Dethridge; ZorbaTHut; venco; and far behind, dmwright, for a mere 260.05 points. At this point everyone had solutions for the Level 1 and Level 2 problems except for dmwright.

The Level 3 problem proved especially difficult. ZorbaTHut had the quickest time, spending 35 minutes on the problem for 521.33 points. SnapDragon had the next submission, for 435.33. With three minutes remaining, reid submitted his Level 3 solution for 481.55 points, and dmwright submitted his Level 1 solution for 260.05 points.

At the end of the Coding Phase, the scores were:

1. ZorbaTHut - 1161.94
2. reid - 1160.36
3. SnapDragon - 1159.17
4. malpt - 706.80
5. John Dethridge - 667.77
6. doeth - 659.65
7. ambrose - 652.55
8. venco - 568.59
9. dmwright - 557.80
Challenge Phase

The first challenge of the night came from dmwright against SnapDragon. dmwright successfully challenged SnapDragon's Level 1 problem with a test case with repeated values for the purchased tickets. SnapDragon obviously did not test his solution on all the sample cases, else he would have caught this simple mistake. dmwright then lost the 50 points he had just gained by unsuccessfully challenging ambrose's Level 1 problem with a similar test case. Unfortunately dmwright made a minor mistake in constructing his test case, accidentally building a case for which ambrose's flawed solution actually succeeds.

venco was next to pick on ambrose, attacking his Level 2 problem. Perhaps venco actually spotted ambrose's mistake, but if so, he failed to form a good test case to exploit it, because his challenge failed. The last challenge came from John Dethridge, who succeeded against ambrose's Level 1 problem where dmwright had failed.

At the end of the Challenge Phase, the scores were:

1. ZorbaTHut - 1161.94
2. reid - 1160.36
3. SnapDragon - 873.09
4. John Dethridge - 717.77
5. malpt - 706.80
6. doeth - 659.65
7. dmwright - 557.80
8. venco - 518.59
9. ambrose - 393.00
System Test Phase

Three submissions failed to pass all of the system tests. As alluded to before, ambrose's Level 2 submission was flawed, due to a mistake in ambrose's treatment of aces. dmwright's Level 1 problem, like SnapDragon's and ambrose's, failed to address duplicate purchases properly (which perhaps explains why he was first to spot the same mistake in the submissions of others). Finally, ZorbaTHut's Level 2 submission failed due to a very obscure fence-post error.

Final Results
1. reid - 1160.36
2. SnapDragon - 873.09
3. ZorbaTHut - 802.75
4. John Dethridge - 717.77
5. malpt - 706.80
6. doeth - 659.65
7. venco - 518.59
8. dmwright - 297.75
9. ambrose - 0.00
By Logan
TopCoder Member