| 1 | (ns adventofcode2019.intcode |
| 2 | [:require [adventofcode2019.lib :refer :all]]) |
| 3 | |
| 4 | ;; 0: function args&mem -> [mem (ctr -> ctr)] |
| 5 | ;; 1: number of args |
| 6 | (defn- decode-op [opcode] |
| 7 | (let [str-code (format "%05d" opcode) |
| 8 | flags (reverse (take 3 str-code)) |
| 9 | op (vec (drop 3 str-code)) |
| 10 | apply-flag (fn [flag arg] |
| 11 | (case flag |
| 12 | ;; ORs avoid returning nil |
| 13 | \0 (fn ([S] (or (get-in S [:memory arg]) 0)) |
| 14 | ([_ _] arg)) |
| 15 | \1 (constantly arg) |
| 16 | \2 (fn ([S] (or (get-in S [:memory (+ arg (:relctr S))]) 0)) |
| 17 | ([S _] (+ arg (:relctr S)))))) |
| 18 | with-flags (fn [f] |
| 19 | (fn [S & args] |
| 20 | (apply f S (map apply-flag flags args))))] |
| 21 | (with-flags |
| 22 | (case op |
| 23 | [\0 \1] (fn [S a b c] ; ADD |
| 24 | (-> S |
| 25 | (assoc-in [:memory (c S true)] (+' (a S) (b S))) |
| 26 | (update :ctr + 4))) |
| 27 | [\0 \2] (fn [S a b c] ; MULT |
| 28 | (-> S |
| 29 | (assoc-in [:memory (c S true)] (*' (a S) (b S))) |
| 30 | (update :ctr + 4))) |
| 31 | [\0 \3] (fn [S a _ _] ; IN |
| 32 | (-> S |
| 33 | (assoc-in [:memory (a S true)] (first (:input S))) |
| 34 | (update :input rest) |
| 35 | (update :ctr + 2))) |
| 36 | [\0 \4] (fn [S a _ _] ; OUT |
| 37 | (-> S |
| 38 | (update :output conj (a S)) |
| 39 | (update :ctr + 2))) |
| 40 | [\0 \5] (fn [S a b _] ; BNEQ |
| 41 | (update S :ctr (if (not= (a S) 0) (constantly (b S)) #(+ % 3)))) |
| 42 | [\0 \6] (fn [S a b _] ; BEQ |
| 43 | (update S :ctr (if (= (a S) 0) (constantly (b S)) #(+ % 3)))) |
| 44 | [\0 \7] (fn [S a b c] ; SLT |
| 45 | (-> S |
| 46 | (assoc-in [:memory (c S true)] (if (< (a S) (b S)) 1 0)) |
| 47 | (update :ctr + 4))) |
| 48 | [\0 \8] (fn [S a b c] ; SEQ |
| 49 | (-> S |
| 50 | (assoc-in [:memory (c S true)] (if (= (a S) (b S)) 1 0)) |
| 51 | (update :ctr + 4))) |
| 52 | [\0 \9] (fn [S a _ _] ; SREL |
| 53 | (-> S |
| 54 | (update :relctr + (a S)) |
| 55 | (update :ctr + 2))) |
| 56 | [\9 \9] (fn [S _ _ _] ; EXIT |
| 57 | (assoc S :exit 1)))))) |
| 58 | |
| 59 | (defn- perform-operation [{:keys [memory ctr] :as state}] |
| 60 | (let [operation (decode-op (memory ctr)) |
| 61 | args (map memory [(+ 1 ctr) (+ 2 ctr) (+ 3 ctr)])] |
| 62 | (apply operation state args))) |
| 63 | |
| 64 | (defn get-program [input-file] |
| 65 | (map parse-int (get-list-from-file input-file) #",")) |
| 66 | |
| 67 | (defn build-state |
| 68 | ([program] |
| 69 | (let [memory (into {} (map-indexed #(vector %1 %2) program))] |
| 70 | {:memory memory :ctr 0 :input [] :output [] :relctr 0})) |
| 71 | ([program settings] |
| 72 | (merge (build-state program) settings))) |
| 73 | |
| 74 | (defn intcode [{:as state :keys [memory output]}] |
| 75 | (cond ; quit if :exit, step and return state if :step, else loop |
| 76 | (get state :exit) {:memory memory :output output :exit true} |
| 77 | (get state :step) (perform-operation state) |
| 78 | :else (recur (perform-operation state)))) |
| 79 | |
| 80 | (defn intcode-until [pred state] |
| 81 | (as-> (assoc state :step true) it |
| 82 | (iterate intcode it) |
| 83 | (drop-while #(not (or (:exit %) (pred %))) it) |
| 84 | (first it) |
| 85 | (dissoc it :step))) |