[Community Puzzle] Bouncing Barry

Coding Games and Programming Challenges to Code Better

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Created by @UnicornP,validated by @Westicles,@MACKEYTH and @FredericLocquet.
If you have any issues, feel free to ping them.

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I just started trying to solve this with C# and I noticed a discrepancy.

The constraints say “1 ≤ bounces per action ≤ 30000”.
However, when I output the array of all of the ‘bounces’ values for Test 08 (‘Just Drunk… -ing’), indexes 108 & 109 show as ‘81779’.

4 Likes

It does look like the constraint is violated or at least some clarification of wording is needed. Would the puzzle author please look into it and fix the puzzle as necessary?

I didn’t solve this game because its too failture.

What? :face_with_monocle:

What’s your issue about it ?

Is it normal that for the test “Sprinting”, there are more bounces than directions?

My code :

print(len(directions))
print(len(bounces))
print(directions)
print(bounces)

Output:

101
139
N E E E W E S E E W E W N W W S W W E W W E W E E E W W W N E E E E E W W E W E W E S N W W E E E S W

1 11 1 8 2 42 1 19 52 31 43 14 1 74 76 1 58 10 1 14 90 2 89 85 54 43 27 70 37 1 51 29 68 83 76 77 36 70 22 14 81 40 1 1 73 36 41 47 88 1 31

Its the same NUMBER of things though.
I think what is confusing you is that:
Each direction is only 1 long
Some bounces are more than 1 long

You need to split the input:

print(len(directions.split()))
print(len(bounces.split()))

Output:

51
51

Hi everyone, I’m still very new to programming and really don’t even know where to start on this puzzle. I was thinking about using nested lists but after a number of tries, I don’t know how to execute on the idea.

The same was true of the Spring 2022 Challenge, until I watched the videos that explain how to store each turn’s inputs using dictionaries. Road to SILVER League - Spring Challenge 2022 - YouTube.

That helped a TON and was pretty much the missing piece I needed. After many hours of tweaking and experimenting I actually got to Gold League, and was able to do other contests with similar techniques. But until I see some kind of tutorial or lesson or whatever, I don’t even know what commands or topics to try to research. Right now I’m just lost.

Is there any article or video like that I can use to at least start to figure out how to generate the kind of grid needed for this puzzle? Or even the name of the type of data structures/commands/techniques that could be helpful? I use Python, btw.

I have the following error on the last test with my Python solution. All other tests are OK. Is there a bug on the test or my solution is wrong?

Erreurs
BrokenPipeError: [Errno 32] Broken pipe

at Answer.py. in main on line 58
at Answer.py. in <module> on line 64

Sortie standard :
................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
...
.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
¤RED¤Fail§RED§
Found:    ".........................................."
Expected: "..........................#.."

Échec
Trouvé : Rien
Attendu : Rien

Hey. ^^

I think you have the same issue I had with my PHP code : you have too much lines to print out because the array indexes used for printing are wrong. Maybe you need to rethink the way you get them to validate the last case.

See Tomorrow why i can’t pass two last tests …

Very curious to show the best solution to understand why i’m not in 100% for this puzzle .

I think a general answer to your question is that

  1. You will recognise the data structure needed with more practice.
  2. A mix and match of different data structures may be necessary.
  3. Understand the properties, advantages and disadvantages of different data structures will help you decide which one(s) suit best. For example, https://realpython.com/python-data-structures.

Send me your script in private, I will send back what’s wrong.

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If you have reached Gold in any Multi, you will soon know what data structure to use out of the box :wink:

For this one you have probably realised 2D array is no-go, since you can reach negative positions vertically/horizontally. Nested list is unnecessary. You need to store whether [X,Y] is marked or not. So just store visited positions in list, set, map (dictionary). If you already have the position stored in your structure, remove it, otherwise add it. Pseudocode:

Set<Position> visited;
if (newPosition in visited) visited.remove(newPosition) else visited.add(newPosition)

You can do printing by computing boundaries - max/min | X/Y…

It was my common mistake trying to represent sparse data as array when I started here :smiley: sparse data belongs to dictionary

I have solved it with a 2D-Array. First round I calculated the Minima and Maxima, then I moved Grid so, that MinX/MinY is at Pos. 0/0 and I moved the Startpoint same. In the second round, Barry bounded.
In the Last Testcase, I first got an “Out of Memory Error” (Array of Boolean). Then I swiched to Bit and it works.

In Python, I used a set that contains the coordinates of the "#" (I discard the coordinates if the point turns into a ".").

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In the description, it’s clearly stated :

Each time Barry lands on a tile, the tile toggles between displaying . and #.

But in the example, on the last instruction W 2, the tile Barry lands on has not switched ?

####
...#
...#
..##

shouldn’t it be

####
...#
...#
.###

?
Am I missing something ? It really messes up my approach of this puzzle tbh

The example in the Goal section is different from the example in the Example section :sweat_smile: One has input of W 1, the other has input of W 2. Is that what confuses you?

1 Like