Spiral Bits

[AMindForeverVoyaging]

Code: Select all

1000 1001 = 0x89 = 137
0101 0000 = 0x50 =  80
0100 1110 = 0x4E =  78
0100 0111 = 0x47 =  71

0111 0110 = 0x76 = 118
1010 1111 = 0xAF = 175
1011 0001 = 0xB1 = 177
1011 1000 = 0xB8 = 184

[sarcasm] Yeah, totally obvious. [/sarcasm]

[MyNameIsAlreadyTaken]

The encoding actually isn't very hard, actually you may know it from some other challenges.



Without spoiling too much: Maybe it isn't such a bad idea to use ASCII in the beginning ;)

[bsguedes]

Well, it is obvious, at least it should be obvious at this point.

The important thing is that you have to be 100% accurate decoding the bits (an ASCII decoding would not need this sort of accuracy)

[AMindForeverVoyaging]

Ah, I should have noticed that sooner.

Ain't it fun to be allowed zero mistakes on 8360 tries

[sergejs]

Ain't it fun to be allowed zero mistakes on 8360 tries

Wait till you get till "Under the sea" challenge

[DaymItzJack]

Ain't it fun to be allowed zero mistakes on 8360 tries

Wait till you get till "Under the sea" challenge

;( so hard....

[AMindForeverVoyaging]

Hmmmm... I guess it would not be that hard to set up a formula for the x and y coordinates to follow the "central line" of the given spiral - if it were not for the pesky fluctuation to the left and to the right.

[laz0r]

Ain't it fun to be allowed zero mistakes on 8360 tries

Wait till you get till "Under the sea" challenge

Under the Sea was easy to automate completely, wasn't it? :/
You're allowed a mistake; brute force helps then! I speak from experience...

[sergejs]

Under the Sea was easy to automate completely, wasn't it? :/

Kinda -- I still needed some googling. Under the sea automation was easier than one for spiral bits, but it took me much more time to make it correct and simple.

As for spiral bits -- knowing the total amount of balls was a huge help for me.

[bsguedes]

Under the Sea was easy to automate completely, wasn't it? :/

Kinda -- I still needed some googling. Under the sea automation was easier than one for spiral bits, but it took me much more time to make it correct and simple.

As for spiral bits -- knowing the total amount of balls was a huge help for me.

I think I have done correctly the automation part in Under the Sea, and I know what to do with the data I get after automation but I don't have the right tool(s)

For Spiral Bits knowing the total amount was also very helpful to me, though finding this number was not the hardest part of the challenge, I think.

[dangermouse]

may I ask if all bits in the picture contribute to the hidden message? or is there some redundancy? just because there are long strides of 0 and 1...

EDIT: never mind, we found the encoding. As suggestion for the next journeyers, we printed the spiral on an A3 paper, and analyzed it deeply.

now, i need to work on the pathfinder part of the challenge. as goodie, you can download here a magnifying glass to debug our breadcrumbs, it's a 16 bit windows app written long time ago. Might the source be with us.

[AMindForeverVoyaging]

I'm still trying to find a way to tackle this challenge.

So my first idea was to use the formula of the Archimedean spiral, but because of the jitter to the left and to the right this does not work, at least not without corrections of some kind.

Another idea I had to traverse the spiral goes something like this:

• 1.) Define possible directions as { up, up/right, right, right/down, down, down/left, left, left/up }
  2.) Define starting point as (x,y) and starting direction as right
  3.) Move (x,y) one pixel in current direction
  4.) Compute "boundary pixels" of (x,y) in such a distance that they are just outside of the spiral, thus black.
  5.) As soon as a "boundary pixel" is not black anymore, a direction in change is needed.
  e.g. if current direction == right and lower boundary pixel is not black anymore, change to right/down
  6.) Repeat 3. to 5. as needed

A problem with this is that this approach needs enough black space around the spiral bits to work, which is not always the case as can be seen in this magnified screenshot: Image Link

So, how do people tackle this? Do you code an exception just for those cases, like filling the data there manually, and then defining a new starting point and direction? Is that a sensible approach?

[Rat62]

I edited the image to get a clear border between the spiral's arms.

[AMindForeverVoyaging]

Huh, I guess that just might work.

Makes me wonder - is there a way to do it without altering the given image?

[bsguedes]

Huh, I guess that just might work.

Makes me wonder - is there a way to do it without altering the given image?

Yes, there is.