# .font: font.text_2
2022-07-14 23:42 dustin  
# .font: font.text_1
finally cso 240 :) it's not the cave i originally had in mind for 240, but the series will continue anyway because i do get new ideas from time to time (at the moment, i've got 5 caves or so in reserve). perhaps 1-2 caves per month :)  
  
this one is inspired by  darkstoorm !

# .font: font.text_2
2022-07-14 23:46 dustin  
# .font: font.text_1
if ^ cannot push the \\, only a strong cso gust can help... :d

# .font: font.text_2
2022-07-15 16:31 nesdori  
# .font: font.text_1
hmm.. in the previous remake cave  dustin  got 42\. this cave's # is 240 which can be represented as reverse decimal notation with trailing zeroes, so 2 and 40 = 42 (this the actual notation my 5 years old daughter used to write down her jump rope records :). the required number of \ is 42 and it feels like that the max speedrun score is 4242.  
  
is  dustin  trying to signal us that the meaning of life is boulder dash? :D

# .font: font.text_2
2022-07-15 17:52 dustin  
# .font: font.text_1
precisely, that was my intention! and if your daughter wants to study anything with computer science, then by the age of 42, she'll surely know that only 40 "plus" 2 is 42 while 40 "and" 2 is of course zero :d

# .font: font.text_2
2022-07-15 21:59 Rob Gilbert  
# .font: font.text_1
i love this series of maps but i admit i have no idea how to approach solving them, they seem to rely on knowing some very specific tricks. is there anything i can read to understand how to solve these caves?

# .font: font.text_2
2022-07-15 22:38 dustin  
# .font: font.text_1
 Rob Gilbert , thanks for the flowers :)   
  
there's a forum thread on  Arno 's website about this whole stuff. (forum - tools, fanstuff - cavescanning order effects or "safely touch fireflies!") in this thread, i explain step by step what cavescanning order (cso) effects are and i also explain in detail how the first 30 caves of this series are solved and why the solutions work as they work.   
  
i also made another thread (the cso university) where i explain in big detail how the bd engine(s) work(s).   
  
have fun with these threads if you like :)  
  
cheers

# .font: font.text_2
2022-07-15 22:44 DarkStoorM  
# .font: font.text_1
Rob: well, rather than looking at the bigger picture - the cave itself - there is a very important detail to keep in mind while playing Boulder Dash: it's the "Cave Scanning Order". Caves are scanned cell-by-cell, from left to right, from top to bottom in one frame and each "scanned" object behaves differently according to a set of conditions these objects meet at the specific point of the scan.  
  
Definitely a great source of information is Dustin's post on Arno's forum: <a href="http://www.boulder-dash.nl/forum/viewtopic.php?t=652&highlight=cave+scannin+order" target="external">http://www.boulder-dash.nl/forum/viewtopic.php?t=652&highlight=cave+scannin+order</a>  
  
You might think some caves look impossible, but when you dive deep enough, you will start understanding why some things work the way you would never expect.  
  
Boulder Dash is a pretty simple game, but with the way how cave scanning works, I believe an extremely complex cave can still be created even with the classic size of 40x22.  
  
Well, it kind of is like a magic trick. You will be blown away just by seeing someone performing it, but when getting the explanation, some tiny details can give everything away.  
  
"The same" situation happens in Boulder Dash: you have two rows of amoeba partially enclosed (opened to the right) and you have to fully enclose it, but you don't have any boulders to help you out and amoeba will not suffocate on its own with two opened rows.  
  
A little trick has to be performed, like running down along the cave scanning order, to trick amoeba into converting it into diamonds, because the top amoeba will be marked as "can't grow anymore", then after Rockford moves down (he gets scanned before the bottom amoeba),  then the bottom amoeba will also be marked as "can't grow anymore", telling the scanner that amoeba has suffocated.  
  
---  
  
All of this comes down to the most important detail: what happens with each object in the cave, scan by scan?  
  
The easiest example would be to take an empty cave filled with space and place two boulders on top of each other, then trying to figure out what will happen to the boulders. Will they both fall down in the same column.  
  
So, going with the cave scanning order, the top boulder will go the first into the scan. Once scanned (if the object is "animate" - basically if it can move), according to the specification, it will attempt to roll to the side, since it is initially stationary, it's left side is just space and the object underneath is "rounded" (boulders and diamonds can roll off of rounded objects). SO, in the result of that, the top boulder will go left, the bottom boulder will just fall.  
  
This is just scratching the surface, I think the Cave Scanning Order topic can be really, really huge, so I recommend reading  dustin 's forum post to get to the real meat :D

# .font: font.text_2
2022-07-15 23:03 dustin  
# .font: font.text_1
the amoeba trick  darkstoorm  mentioned can be seen, among other caves, in cso 10 ;)

# .font: font.text_2
2022-07-15 23:07 DarkStoorM  
# .font: font.text_1
Yes  dustin , this is exactly the cave I looked at for this ;)  
  
By the way! This cave was nice to figure out, except I had to go with trial and error, then observe the stacks in cave speed = 3 :D

# .font: font.text_2
2022-07-16 00:38 dustin  
# .font: font.text_1
 darkstoorm , i also trial-and-errored the left side. i was about to give up but then i discovered a way to do it!   
  
for the right side, i made a full cso analysis to understand how these \\\ pyramids work. it's quite a fascinating principle!

# .font: font.text_2
2022-07-16 07:20 Rob Gilbert  
# .font: font.text_1
oh, very cool! thanks for the explanations, i'll do some research on the cave scanning order intricacies, sounds fascinating!

# .font: font.text_2
2022-07-16 13:59 nesdori  
# .font: font.text_1
interesting.. i moved only on the bottom diamond row to convert both heavy |. the right side is of course obvious and i knew the general concept for the left side from other caves. still took some tries to find one of timings that works. i wonder if you did something else to handle the left side?

# .font: font.text_2
2022-07-16 14:57 DarkStoorM  
# .font: font.text_1
 nesdori , have you descended to the magic wall row with all the diamonds on both sides? I only did it with the left side :D  
  
I see there are two solutions to the right side - and I guess possibly even more if we count some minor variants

# .font: font.text_2
2022-07-16 15:00 nesdori  
# .font: font.text_1
 darkstoorm , no, i didn't touch dirt until i had to go to the exit :)

# .font: font.text_2
2022-07-16 17:13 DarkStoorM  
# .font: font.text_1
Okay, that's interesting :D I thought it was required for the left side to drop the diamonds so the boulder gets a proper slope

# .font: font.text_2
2022-07-16 17:20 dustin  
# .font: font.text_1
 nesdori , yes i did the left side differently, but after reading that it's possible only by collecting the bottom \\\, i needed only one try to do it that way d

# .font: font.text_2
2022-07-16 20:06 nesdori  
# .font: font.text_1
 dustin  :D

# .font: font.text_2
2022-07-19 23:29 dustin  
# .font: font.text_1
my runs free!  
  
2437 is the intended solution (the first one i found), while 4238 might be easier to perform, especially for a 5-year-old girl ;)

# .font: font.text_2
2022-07-20 00:00 DarkStoorM  
# .font: font.text_1
And here's mine :D