#day 1

+/INPUT

{1↑{((⍵⍳⍵)≠⍳⍴⍵)/⍵}+⍀0,1000000⍴⍵}INPUT


#day 2

⍝ part 1 dyalog

 ×/¨+/{0<+/⍉{{{(2=⍵),(3=⍵)}2⊃⍵}⍺,≢⍵}⌸⍵}¨



⍝ part 2

⍝ boolean if two vecs are one item off
'abc' {(¯1+⍴⍵)=+/⍺=⍵} 'abz'

⍝ need to select only matching letters here
'abc' {(1+(¯1+⍴⍵)=+/⍺=⍵)⌷0 (⍺=⍵)} 'abz'

⍝ Remove characters!!!
{(~⍵∊' ')/⍵}'1 2'

⍝ Our dydactic solution fn
'abc' {(1+(¯1+⍴⍵)=+/⍺=⍵)⌷0 ⍵[{(~⍵∊0)/⍵}(⍺=⍵)×⍳⍴⍵]} 'abz'

ONEOFF←{(1+(¯1+⍴⍵)=+/⍺=⍵)⌷0 ⍵[{(~⍵∊0)/⍵}(⍺=⍵)×⍳⍴⍵]}

⍝ now run permutations on each string
⊃1↑{(~⍵∊0)/⍵},{⍵ ∘.{(1+(¯1+⍴⍵)=+/⍺=⍵)⌷0 ⍵[{(~⍵∊0)/⍵}(⍺=⍵)×⍳⍴⍵]} ⍵} INPUT

]BOXING ¯29

⍝ load a file
INPUT←⎕FIO[49]'data/2018.3.txt'


# DAY 3
⍝ part 1 

DIMS←{⊃1↓⍎¨⍵}¨{(1≠⍵∊' #@,:x') ⊂ ⍵}¨INPUT

GRID←1000 1000⍴0

⍝ matrix of indicies into the grid
{((2↓⍵)⍴⊂(2↑⍵))+⍳⍴(2↓⍵)⍴0} 3 4 5 2
⍝ inc a coord
{GRID[1⌷⍵;2⌷⍵]←1+GRID[1⌷⍵;2⌷⍵]}3 4

⍝ tally
{+/+/⍵>1}GRID

⍝ one liner
{+/+/⍵>1}GRID⋄{{GRID[1⌷⍵;2⌷⍵]←1+GRID[1⌷⍵;2⌷⍵]}¨{((2↓⍵)⍴⊂(2↑⍵))+⍳⍴(2↓⍵)⍴0}⊃⍵}¨DIMS⋄GRID←1000 1000⍴0



⍝ part 2 

DIMS←{⊃⍎¨⍵}¨{(1≠⍵∊' #@,:x') ⊂ ⍵}¨INPUT

⍝ initialize
SET←0⍴0
GRID←1000 1000⍴0

⍝ set functions
HAS←{+/⍺∊⍵}
DSTNCT←{((⍵⍳⍵)=⍳⍴⍵)/⍵}
CONJ←{SET←(SET,⍵)}

⍝ IMPL
INDGRID←{((2↓⍵)⍴⊂(2↑⍵))+⍳⍴(2↓⍵)⍴0}

⍝ given an id and coords, if coord allready has id, add both to SET
⍝ then write new id to coords
WRITE←{GRID[2⌷⍵;3⌷⍵]←1⌷⍵} ⍝8 4 4

⍝ if loc != 0 CONJ loc value and new value
SCORD←{CONJ ⊃(((1⌷⍵) GRID[2⌷⍵;3⌷⍵]) 0)[((0=GRID[2⌷⍵;3⌷⍵])+1)]} ⍝6 4 3

DIMS←10↑DIMS

⍝ create the coord rect matrix, then record and check
⍴{{WRITE ⍵,SCORD ⍵}¨(1⌷⍵),¨INDGRID 1↓⍵}¨DIMS ⍝ 55 3 4 5 2

⍝ make an actual set
SET←DSTNCT SET

⍝ find id not in SET
+/{⍵×0=SET HAS ⍵}¨1↑¨DIMS