??? LCIPC Query Board ???

LCIPC Query Board

All queries will be posted to this page, please check postings frequently.

Send all queries to: lchs3@hotmail.com

cep21:
Q: "If two towers are equally close to the base, John will choose thetower which has the lower number (ex: If B and E are tied, he will choosetower E to connect to)." Lower number of what?

Judge's Response:
A: Unfortunately, that is a typo. It should say, "If B and E are tied, he will choose tower B to connect to."

cep21:
Q: If John is at 0,0 and a babe is at 2,2 but an opstruction is at 1,1 - 2,0 will John be able to see the babe? In other words, if there is an opstruction 'corner' can John see past the corner?

Judge's Response:
A: The answer to both questions is no.

Jose Santos:
Q: In problem 1 you say..."If two towers are equally close to the base, John will choose the tower which has the lower number (ex: If B and E are tied, he will choose tower E to connect to)."
How can this be ?
I suppose it'll choose tower B, and not E, right ? was it just a typing mistake, or you meant the higher number?

Judges Response:
A: It is a typo. B should be chosen.

cep21:
Q: Does your total "running" time include compile time, or is it thetime the .exe runs???

Judges Response:
A: As the programs are received, they are compiled. The grader program then tests the program and counts only the run time of the program, not the appoximately half-second of program load time. If the program runs in 5 seconds or less and outputs the correct answer, the program receives full credit for that input case. If the program completes running in 7.50 seconds or less and outputs the correct answer, it will receive partial credit.

Milan Stanojevic
Q: Problem #1:
If there are several optimal ways to connect the towers, which oneshould we choose? Location of the meeting point depands on how we choose the connection beetween the towers.

Judges Response:
A: There will always be one optimal way to connect the towers according to the cost matrix, but there may exist multiple optimal meeting points depending on the distance matrix.

Chuong Do:
Q: Perhaps I'm not reading the question carefullyenough, but L.C. John is said to have differentspeeds on sand and sidewalk. So, does thatmean that the lifeguards will always walk on thesidewalks? and that John will always walk on eithersand or the sidewalk, but not both? Or does itmean that John may choose to walk on the sidewalkto Tower 1 where he then walks across the sand toTower 2?

Judges Response:
A: Yes, No, Yes
The reason for this is that L.C. John is on foot and thus runs differently on sand or pavement and that the lifeguards are roller skating so they must travel on pavement.

Bob:
Q: Problem #1:
does john minimize the total path length or the total path time in going from tower to tower?

Judges Response:
A: Time

Bob:
Q: are both the cost and distance matrices symmetric? (cost(i,j)=cost(j,i) and dist(i,j)=dist(j,i)?)

Judges Response:
A: Yes

Marián Dvorský:
Q: Problem 1:
Are you sure that John's speeds are in units/SEC and lifeguards' speed inunits/MIN? I think that you meant both in units/MIN.

Judges Response:
A: Urgh! Sorry, it is a typo. They should both be units/min.

Milan Stanojevic:
Q: But then again, problem description states that there will be ONEoptimal meeting point. What is correct: multiple or one? The onlyproblem with this is what point should be printed if there are multiple optimal points.

Judges Response:
A: There will never be a tie as to which meeting place is more optimal.There will be a clear optimal meeting place.

Kelvin Lim:
Q: About problem 3 ("Cooler Stacking"), what should the output be like if N=1, ie. there is only one cooler, so no action is required?

Judges Response:
A: N won't be 1.

Justas Kranauskas:
Q: Can surfer John sit in the same place where sits a babe?

Judges Response:
A: Yes

Justas Kranauskas:
Q: What is supposed to be a convex_hull in challenge problem, ifonly one babe is visible? if only two babes are visible?

Judges Response:
A: If only one babe is visible, the perimeter of the convex hull is 0. If two babes are visible, the perimeter of the convex hull is equal to twice the distance between the two babes.

Michael Craig:
Q: is the contest over at midnight Saturday (as soon as Saturday begins), or as soon as Saturday ends?

Judges Response:
A: As soon as Saturday ends

Rusmin Soetjipto:
Q: Will LC John ever have faster speed on sand than on pavement? If so, can we tell him to walk through the pavement, but with sand speed (suppose LC John walks exactly on the sand beside the pavement) ?

Judges Response:
A: If there is pavement between two towers, LC John will always walk on the pavement. No response to first question.

Chuong B Do:
Q: In the list of rules, the header file <iomanip.h> is not allowed, yetit provides important floating point output manipulation routines.Will that be allowed?

Judges Response:
A: Yes. It should be added to the list of supported header files.

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