brycesandlund's blog

2017 North Central North America ACM-ICPC Regional
By brycesandlund, history, 7 years ago, In English

Hi all,

The 2017 North Central North America ACM-ICPC Regional Programming Contest is tomorrow. Our region hosted the World Finals last year. There is an open division for anyone who is interested in competing, link here: https://open.kattis.com/contests/ncna17open. Official scoreboard will be live at https://ncna17.kattis.com/ at 4pm UTC tomorrow.

Myself and Dr. Larry Pyeatt of SDSMT primarily created the problem set, with the help of: Robert Hochberg, Bowen Yu, y0105w49, Menghui Wang, Andrew Morgan, The East Coast North America regional problem development team, and especially, the Kattis team, specifically Fredrik Niemela and Greg Hamerly, to which we are very grateful.

Good luck to all contestants tomorrow!

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7 years ago, # |
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There is a important clarification on problem Atlantis. I'm told it cannot be made available to the open contest. To this I am very sorry for team "TooWeakTooSlow". The clarification is:

Important: The gold store must remain above water during the ENTIRE trip to and from the store.

EDIT: The problem statement has been updated. Hope this helps.

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    7 years ago, # ^ |
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    What happens when water level reaches the height at the same time when the person reaches back to the ship? The first test case suggests that we should consider it valid.

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      7 years ago, # ^ |
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      Yes, if you arrive back at the ship at the same time the gold store is submerged, this is valid.

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7 years ago, # |
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How to solve E: "Is-A? Has-A? Who Knowz-A?"?
I am stuck with the WA2.

code
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    7 years ago, # ^ |
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    Short answer: A is-a B iff there is a path of is-a relationships from A to B. A has-a B iff there is a path of is-a and has-a relationships from A to B that includes at least one has-a relationship.

    Long answer: Make sure you check your relationships correctly. I'll be posting solution slides over the weekend, as well as the complete judging data.

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    7 years ago, # ^ |
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    Your Floyd-Warshall is incorrect.

    Sample case: A has-a B is-a C has-a D is-a E has-a F is-a G will yield that A has-a G.

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      7 years ago, # ^ |
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      But A has-a G!

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        7 years ago, # ^ |
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        Oh, sorry, you're saying that his code says A does not have a G whereas the correct answer says that A has-a G.

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7 years ago, # |
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my solutions: https://aleigorithms.wordpress.com/2017/10/28/2017-north-central-na-regional-contest-open/

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    7 years ago, # ^ |
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    Yet another way to solve Atlantis! I have found a number of solutions to this problem.

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      7 years ago, # ^ |
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      Actually, did you typo your solution for Atlantis? T[i] is a strictly increasing function, so it doesn't make sense to remove the one with greatest T[i].

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