[Community Puzzle] Skylines

Puzzles
1

Coding Games and Programming Challenges to Code Better

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2

is anyone able to get me the input lists for validator 8 and 10. I keep failing on them for hours and have no idea why

2 Likes
3

I had a similar issue, it seems that a h x1 x2 building begins in x1 but ends in x2 - 1

3 Likes
4

I can’t find a better place to put my question/optimization of the puzzle so i will do it here:

I made a solution that failed 2 of the viewable Test cases (06 and 10) but got 100% on Submitting. I have no idea why these two examples do not work and if it’s an issue for the creator that i got 100% with a wrong solution.

Any ideas what i should do?

5

summoning @Heino

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Test cases 6 to 10 are not generated by hand but instead a parameterized program was used to generate the inputs (with the help of a random generator).
Obviously the viewable test cases contain some features that are not covered by the private validators and vice versa. So @Shiggy, you are very lucky that you got a 100% score, although the program is most likely not entirely correct. And @nphect probably has an error in his code too, otherwise the validators would succeed.

To make it clear: When a building ends at e.g. x2=10 and a second building starts at x1=11, then there is a gap between the two buildings. That means you need 7 lines to draw both.

1 Like
7

Hello guys,

What about validator 5 ?
I passed all test cases and all validators except this one.
Thanks !

8

I’ve been mighty annoyed by these validators too.

Quite a few things are not clearly stated in the problem definition:

  • is the x2 coordinate part of the building or not?

  • what should we do at the edges of the picture? Should a zero height line be drawn left and right?

  • should we draw a line between two buildings of the same height, i.e.

     _     _      _ _       ___
| | + | | =  | | |  or |   | ?

Though the problem definition seems to say that’s 5 lines anyway, that contradicts the intuitive definition of a skyline and nothing specific is said about that.

The tests don’t check any of these edge cases. I had a program passing all tests within 10 minutes, but I spent ages fiddling with various combinations of hypothesis until the damn validators turned green.

9

For those who are stuck debugging, here is a similar problem with almost the same input format (simply x1 h x2 instead of h x1 x2) and here are some hopefully helpful testcases for debugging purposes.