[Community Puzzle] Bouncing Barry

Puzzles
#21

Technically possible, but you have to go through all instructions twice right?
Also “Out of Memory” sounds like not ideal :slight_smile: But why do I care if it works…

#22

No, I just check each visited cell, following Barry’s bounces…

#23

Yes, correct. First, I only check the extremes, and second, I can “use” the calculated Grid.
Pascal seems to be fast enough.
The “Out of memory” only rises with the array-type “Boolean”, because a Boolean uses one Byte. After changing to Bits and Bytes, the memory-problem didn’t rise again. And with simple boolean algebra, the result is faster too, I think.

#24

In Javascript/Typescript I had a lot of problems to pass Test 08 (‘Just Drunk… -ing’) due to a heap out of memory error because I used a 2D array of booleans for the grid. In the end I solved it using this bit array class, which I would like to share here:

class BitArray {
    constructor(length) {
        this.uint32Arr = new Uint32Array(Math.ceil(length / 32));
        this.length = length;
    }
    get(n) {
        return (this.uint32Arr[Math.floor(n / 32)] & 1 << n % 32) !== 0;
    }
    on(n) {
        this.uint32Arr[Math.floor(n / 32)] |= 1 << n % 32;
    }
    off(n) {
        this.uint32Arr[Math.floor(n / 32)] &= ~(1 << n % 32);
    }
    toggle(n) {
        this.uint32Arr[Math.floor(n / 32)] ^= 1 << n % 32;
    }
    isZero() {
        return this.uint32Arr.every(num => num === 0);
    }
}

Still, I’m a little bit disappointed that this puzzle doesn’t respect the “1 ≤ bounces per action ≤ 30000” constraint.

#27

Sure? My problem is, that I am the only Pascal-Coder at this event. But I want to see other solutions too.
If you’re right, I only have to send a TestCase in the Language, that I want to see later? Or is it necessary to Submit some code?
And did it work, even the code isn’t correct?

Actually I can read:
“The solutions below will be available when you have solved this puzzle by yourself in the selected language.”

#28

The previous experience is that “you have solved” actually means “you have tried to solve” :thinking:

#29

You do this in ANY language (just 1) and you will see the top3 solutions in ALL languages (provided there were 3 solutions in that language… so your Pascal solution will remain a well kept secret :slight_smile: )

#30

Damn, you’re right, my bad :sweat_smile:

1 Like
#33

UPDATE: Once I selected “C#” instead of just leaving it as “All programming languages” then I could see 3 solutions in C#, which is what I was seeking. Yippee :slight_smile: – Thanks for the help :slight_smile:

#35

Dang, some of the solutions are soooo elegant.
Nothing like I was trying to pound out for hours. Much respect to those who solved this :slight_smile:

1 Like
#36

Thx, i’ve found my mistake with the reviews of challenges…

Every day make us better on the long long road of code :crazy_face:

#37

Continuing the discussion from [Community Puzzle] Bouncing Barry:

This puzzle was a lot of fun! I have some feedback on it that I thought I’d share:
When I was debugging Test 08 (‘Just Drunk… -ing’) I wrote a “brute force” function that simply walked the path and toggled an entry for every point, just so I could make my own small-scale tests and know what the output should look like.

It turns out, that function was good enough to pass all the validator tests, and it’s also how all the solutions I’ve seen have done it. The wording in the brief and the given constraints suggested a harder problem where brute force wouldn’t work, so I had something more complicated in mind. I decided to finish it anyway for the novelty.

I won’t spoil how I solved it here, since this could easily be turned into a harder puzzle with some more demanding validators. Instead, I have some tests that all posted solutions I’ve seen (including the authors) will fail.

496 Actions, 30000 Bounces per Action:
Here’s a test that’s almost maxing out the constraints

S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W S E N W
30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000 30000

Barry Toggled Something Afar:
This test uses actions with 60,000 bounces, but all solutions had to deal with that in the validators, so we also have 256 actions.

E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S E S W S N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W N E N W 
60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 60000 1 59999

Fit Bunny (800M Bounces):
This one should make it clear that we’re not bouncing along with Barry anymore.

N E S W N E S W
100000000 100000000 100000000 100000000 100000000 100000000 100000000 100000000

Ideas:
Would love a harder version to see the unique ways people find to optimize the code.
A twist where you’re given the floor and asked to trace back the shortest sequence needed for Barry to reproduce it. (this one hurts just thinking about it)

Anyway, that’s all I had to add. Thanks for the puzzle!

#38

Oops, sorry for the late response, I was on hiatus for the past month or so. The constraints are now fixed (1 ≤ bounces per action ≤ 100000). As far as I can imagine, no working solution would be affected by 30K vs 100K, whereas the other option of regenerating a valid test case for Drunk with bounces < 30K is tedious. Of course, if 100K does in fact cause issues, then tell me and hope that I’m paying attention to the forum :stuck_out_tongue: .

I also fixed the example in the Statement so it doesn’t look like Test #1.

As for BHW’s suggestions: pretty cool! In fact, this puzzle was originally conceived as a CoC, but people complained that it was too hard for 15 minutes. Since I still wanted to keep the simplicity but make it just a bit harder to fit an Easy puzzle, this is the end result. And then it ended up Medium anyway. No plans to make a harder version, so feel free to extend it if you want.

#39

:wave: Hi @UnicornP … thanks for this tweaked Puzzle :+1: … and Hi to all too :wink: !

I’ve just submit my code (this one in Python), but the 7th Validator fails, where as 100% pass in the IDE …
→ can the Author, or anyone else, help me to find where is my :bug: bug, or what is special in this 7th Validator from all the others Validators and IDE test cases, please ?

Thanks by advance :pray: …
@Jp82

#40

Validator 7 (“Validator Sprint”) has more than 100 lines of less than 10 characters each in the output. Not sure if that information helps you :sweat_smile:

You may send me your code to have a look if you want.

1 Like
#41

OK, Thanks @5DN1L for your help :+1: …
→ Working around your custom similar TestCase,
=> I finally found a 100% Validator Solution :wink: !

1 Like