adventofcode2021.bqn

advent_01.bqn

p ← •BQN ¨ •file.Lines ⊑ •args
T1 ← +´1↓»⊸<
T2 ← +´˘3↕⊢
•Show T1 p
•Show T1∘T2 p

advent_02.bqn

val ← ⊐⟜' '⊸(↑⋈1↓↓)¨•Flines "ex-1.txt"

mov ← "forward"‿"down"‿"up"⊐(0⊑¨val)
amt ← •BQN¨1⊑¨val

•Show (×´+´) amt × mov ⊏ ⟨1‿0, 0‿1, 0‿¯1⟩

F ← +´0⊑¨⊢
D ← +´(1⊑¨⊢)×(+`2⊑¨⊢)

•Show (F×D) amt × mov ⊏ ⟨1‿1‿0, 0‿0‿1, 0‿0‿¯1⟩

advent_03.bqn

val ← ∾˘'1'=¨ •Flines "problem-01.txt"

Len ← {1⊣´≢𝕩}
Base2 ← +⟜(2⊸×)´∘⌽

n ← Base2 ((Len val)÷2) < +´<˘val
m ← Base2 ((Len val)÷2) > +´<˘val

•Show n × m

OGR ← ⥊∘{x←𝕨⊑˘𝕩 ⋄ i←(0.5≤(+´x÷(Len 𝕩))) ⋄ (𝕨+1) {1<(Len 𝕩)}◶⊢‿𝕊 ((i⊑(⊔x))⊏𝕩)}
CSR ← ⥊∘{x←𝕨⊑˘𝕩 ⋄ i←(0.5>(+´x÷(Len 𝕩))) ⋄ (𝕨+1) {1<(Len 𝕩)}◶⊢‿𝕊 ((i⊑(⊔x))⊏𝕩)}

•Show  (Base2 ∘ OGR val) × (Base2 ∘ CSR val)