somehow I guess this is unary even though there are two states

So I'm working on a solution for Project Euler Problem 18 (and by extension 67) and just trying to find a good way to represent the binary tree in APL is an interesting challenge in and of itself

Not in front of a computer but isn't this something like ⊃⊃{⍺+0,⍨2⌈/⍵}⌿triangle?

⋄ b ← 4 4 ⍴ 8 5 9 3 2 4 6 0 7 4 0 0 3 0 0 0 ⋄ ⎕←{⊃{(2↓⍵)⍪⍨⌈/¨{(2|⍳⍴⍵)⊂⍵}2+/,⍉2↑⍵}⍣(¯1+⊃⍴⍵)⊢⍵}b

@Sherlock9
23

Ah. I had something quite a lot longer XD

Oh wait that's for the formatting ohhh

⋄ b ← 4 4 ⍴ 8 5 9 3 2 4 6 0 7 4 0 0 3 0 0 0 ⋄ ⎕←⊃{{(2↓⍵)⍪⍨(1↓2↑⍵)+0,⍨2⌈/1↑⍵}⍣(¯1+⊃⍴⍵)⊢⍵}b

@Sherlock9
23

This is shorter but still not great

@TessellatingHeckler ⊥ doesn't care if you have "invalid" digits. a⊥x y z is always xa²+yx¹+zx⁰, so for a=1, x=2, y=0, z=3, you get a2×1²+0×1¹+3×0⁰=5, i.e. the sum, +/ (well, +⌿ to be precise).

⋄b ← 4 4 ⍴ 8 5 9 3 0 2 4 6 0 0 7 4 0 0 0 3⋄⎕←⊃⌽{{(2↓⍵)⍪⍨(1↓2↑⍵)+0,2⌈/1↑⍵}⍣(¯1+⊃⍴⍵)⊢⍵}b ⍝ rearranging the triangle

⋄ b ← 4 4 ⍴ 8 5 9 3 0 2 4 6 0 0 7 4 0 0 0 3 ⋄ ⎕←⊃⌽{{(2↓⍵)⍪⍨(1↓2↑⍵)+0,2⌈/1↑⍵}⍣(¯1+⊃⍴⍵)⊢⍵}b ⍝ rearranging the triangle

@Sherlock9 Don't use comments!

Ah, nuts

⎕←⊃⌽{{(¯2↓⍵)⍪(1↑¯2↑⍵)+0,2⌈/¯1↑⍵}⍣3⊢⍵}4 4 ⍴ 0 0 0 3 0 0 7 4 0 2 4 6 8 5 9 3

@Sherlock9
23

Internally, the bot inserts your code into a dfn, but a comment symbol will terminate the line and so no } is found…

Oh whoops

Hrm, there has to be a golfier way to do the whole problem than just (grabbing a last line, taking the pairwise max, adding it to the second-to-last line, and appending that new line to the rest of the array), but I'm not seeing it

@Sherlock9 reduce? i haven't really analyzed what the code is doing but you seem to be describing it

⋄ prob18 ← {(¯2↓⍵)⍪(1↑¯2↑⍵)+0,⍨2⌈/¯1↑⍵} ⋄ ⎕←prob18/ 4 4⍴3 0 0 0 7 4 0 0 2 4 6 0 8 5 9 3

@Sherlock9
┌─┬─┬─┬─┐
│0│0│0│0│
└─┴─┴─┴─┘

⋄ prob18 ← {(¯2↓⍵)⍪(1↑¯2↑⍵)+0,⍨2⌈/¯1↑⍵} ⋄ ⎕←prob18 4 4⍴3 0 0 0 7 4 0 0 2 4 6 0 8 5 9 3

@Sherlock9
 3  0  0 0
 7  4  0 0
10 13 15 0

Reduce could work, but something tells me my function is set up wrong

@Sherlock9 do ↓ on the input to get the lines as ⍺ & ⍵

@dzaima How do you mean?

⎕←{{⍺,⍵}↓⍵}4 4⍴3 0 0 0 7 4 0 0 2 4 6 0 8 5 9 3

@Sherlock9
VALUE ERROR

@Sherlock9 something like {...}/↓⍵

may need to reverse the input list though as you start with the first two lines, not the last

Almost works

Actually, hang on

⎕←{⍺+0,⍨2⌈/⍵}/↓↑(8 5 9 3)(2 4 6)(7 4)3

@Sherlock9
┌──────────┐
│20 13 15 3│
└──────────┘

None of those are the correct answer of 23, but it's an interesting start

⎕←{⍺+0,⍨2⌈/⍵}/↓(8 5 9 3)(2 4 6)(7 4)3

@Sherlock9
┌─────────────────────┐
│┌───────┬─────┬───┬─┐│
││8 5 9 3│2 4 6│7 4│3││
│└───────┴─────┴───┴─┘│
└─────────────────────┘

And this doesn't work at all

⎕←{⍺+0,⍨2⌈/⍵}/(8 5 9 3)(2 4 6)(7 4)3

@Sherlock9
RANK ERROR

Nor this

Oh the 0,⍨ shouldn't be there but that doesn't resolve the rank error

@Sherlock9 reverse the input

... That was the original input order of the question and I reversed it on being asked to reverse it the first time XD

⍨⍤⍣

Hooooly cow this has over 500 unread messages. That's a first for me.

@J.Sallé What has?

@Adám first time I've seen this chat with over 500 unread messages. It usually doesn't accumulate so much

Guess I was working a bit more yesterday and didn't have time to check here

⎕←⊃⊃{⍺+0,⍨2⌈/⍵}/↓↑(3)(7 4)(2 4 6)(8 5 9 3)

@voidhawk
23

@Sherlock9 applying that brings it down to a beautiful {⍺+2⌈/⍵}/

@dzaima Ooh excellent

Hm, should I try to do partition numbers (problem 78) or go take a nap XD

@Sherlock9 ⎕DL&3600 lets you sleep for an hour while you keep working!

Thanks! I'm already home from work though :D

Also note that ⎕DL&¨2/1800 lets you sleep for an hour while only 30 mins pass.

@Adám Welp, I now know which language to code my time machine in.

@J.Sallé John Scholes once rigged a presentation of his so that all of a sudden a number was printed into his session, to which he remarked that he doesn't know where that came from,. Then a while later during his demonstration he wrote ⎕DL with a negative number, and then commented that now he knows where that number had come from.

I do love me some nerdy jokes.

@Adám I've gotten a nonce error, which I've never seen before, running this code ⍸{1pco⌊○10*⍵-1}¨⍳10. I think it's pco throwing it, but I'm not sure. What does it mean?

It runs fine for ¨⍳9, that's why I think it's pco's fault

I've tried setting ⎕FR←1287 and ⎕PP←34 to no avail.

@J.Sallé nonce seems to only be happening in extended, in unicode it's giving domain error, i'm assuming that's pco just refusing to work with numbers that big no matter what

nonce error

@dzaima Yeah, I looked into the function and it doesn't work for numbers over 105097564

⋄←⎕CY'dfns' ⋄ 1pco(1e9)

@J.Sallé
SYNTAX ERROR

oh well

I tried

this is what I tried to do

huh, in code it's domain error

@Adám if that's a base conversion, should it say xa²+ya¹+za⁰ instead of xa²+yx¹+zx⁰ ?