master
Matthew Butterick 4 years ago
parent 16e6e2b131
commit c89b474616

@ -1,24 +1,25 @@
#lang br
(require racket/file rackunit)
(require racket/file rackunit racket/generator)
(define (string->regs str)
(list->vector (map string->number (string-split str #px",\\s*"))))
(define (string->ints str) (map string->number (string-split str #px",\\s*")))
(define (string->regs str) (list->vector (string->ints str)))
(define ((binarize proc) x y) (if (proc x y) 1 0))
(define (run str starting-input)
(define (run str . inputs)
(define regs (string->regs str))
(define (reg-ref ptr) (vector-ref regs ptr))
(define (reg-set! ptr val) (vector-set! regs (reg-ref ptr) val))
(define ip (open-input-string (string-join (map ~a inputs) " ")))
(let/ec terminate
(let loop ([ptr 0])
(match-define (list opcode mode-1 mode-2 mode-3)
(match (for/list ([c (in-string (~r (reg-ref ptr) #:min-width 5 #:pad-string "0"))])
(string->number (string c)))
(string->number (string c)))
[(list d4 d3 d2 d1 d0) (cons (+ (* 10 d1) d0)
(for/list ([mode-val (list d2 d3 d4)]
[offset '(1 2 3)])
(λ (ptr) ((if (zero? mode-val) reg-ref values) (reg-ref (+ ptr offset))))))]))
(λ (ptr) ((if (zero? mode-val) reg-ref values) (reg-ref (+ ptr offset))))))]))
(define next-ptr
(match opcode
[(or 1 2 7 8) ; 4-arity: add & multiply & compare
@ -30,7 +31,8 @@
(+ ptr 4)]
[(or 3 4) ; 2-arity: input & output
(match opcode
[3 (reg-set! (+ ptr 1) starting-input)]
[3 (parameterize ([current-input-port ip])
(reg-set! (+ ptr 1) (read)))]
[4 (println (mode-1 ptr))])
(+ ptr 2)]
[(or 5 6) ; 3-arity: jump
@ -46,23 +48,19 @@
(define-syntax-rule (last-output func)
(last (map string->number (string-split (with-output-to-string (λ () func))))))
(check-eq? (last-output (run "3,0,4,0,99" 42)) 42)
;; 1
(check-eq? (last-output (run (file->string "05.rktd") 1)) 15386262)
(check-eq? (last-output (run "3,9,8,9,10,9,4,9,99,-1,8" 8)) 1)
(check-eq? (last-output (run "3,9,7,9,10,9,4,9,99,-1,8" 8)) 0)
(check-eq? (last-output (run "3,3,1108,-1,8,3,4,3,99" 8)) 1)
(check-eq? (last-output (run "3,3,1107,-1,8,3,4,3,99" 8)) 0)
(check-eq? (last-output (run "3,12,6,12,15,1,13,14,13,4,13,99,-1,0,1,9" 0)) 0)
(check-eq? (last-output (run "3,3,1105,-1,9,1101,0,0,12,4,12,99,1" 0)) 0)
(define (thruster-signal program phases)
(for/fold ([input 0])
([phase (in-list (if (string? phases) (string->ints phases) phases))])
(last-output (run program phase input))))
(let ([str "3,21,1008,21,8,20,1005,20,22,107,8,21,20,1006,20,31,
1106,0,36,98,0,0,1002,21,125,20,4,20,1105,1,46,104,
999,1105,1,46,1101,1000,1,20,4,20,1105,1,46,98,99"])
(check-eq? (last-output (run str 0)) 999)
(check-eq? (last-output (run str 8)) 1000)
(check-eq? (last-output (run str 10)) 1001))
(check-eq? (thruster-signal "3,15,3,16,1002,16,10,16,1,16,15,15,4,15,99,0,0" "4,3,2,1,0") 43210)
(check-eq? (thruster-signal "3,23,3,24,1002,24,10,24,1002,23,-1,23,
101,5,23,23,1,24,23,23,4,23,99,0,0" "0,1,2,3,4") 54321)
(check-eq? (thruster-signal "3,31,3,32,1002,32,10,32,1001,31,-2,31,1007,31,0,33,
1002,33,7,33,1,33,31,31,1,32,31,31,4,31,99,0,0,0" "1,0,4,3,2") 65210)
;; 2
(check-eq? (last-output (run (file->string "05.rktd") 5)) 10376124)
;; 1
(check-eq?
(apply max (for/list ([phases (in-permutations '(0 1 2 3 4))])
(thruster-signal (file->string "07.rktd") phases)))
87138)