Day 11 shorter and faster with n-wise reduction.

jayfoad · Dec 11, 2018 · 3bed3ac · 3bed3ac
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+⎕IO←1
+p←⍎⊃⊃⎕NGET'p11.txt'1
+g←{r y←10 0+⍵ ⋄ ¯5+10|⌊100÷⍨r×p+y×r}¨⍳300 300 ⍝ grid
+⊃⍸{⍵=⌈/,⍵}3+/3+⌿g ⍝ part 1
+1↓{(⊃⍒⍵)⌷⍵}↑1{0>m←⌈/,t←⍺+/⍺+⌿g:⍵ ⋄ (⍺+1)∇⍵,⊂m,(⊃⍸m=t),⍺}⍬ ⍝ part 2