:import std/Combinator .
:import std/String .
:import std/Number .
:import std/Char C
:import std/Pair P

self [[((zip 0) ∘ (drop 1) ∘ cycle) 0]] ⧗ Number → (List Number) → (List (Pair Number Number))

part1 sum ∘ eqs ∘ pairs
	sum foldl [[^0 + 1]] (+0)
	eqs filter (P.uncurry …=?…)
	pairs self (+1)

part2 [(sum ∘ eqs ∘ pairs) 0]
	sum foldl [[^0 + 1]] (+0)
	eqs filter (P.uncurry …=?…)
	pairs self /²(length 0)

:test (part1 ((+1) : ((+1) : ((+2) : {}(+2))))) ((+3))

main [parts nums]
	nums C.char→number <$> ^(lines 0)
	parts [(part1 0) : (part2 0)]