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c0464c3a JK |
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 | |
cce51437 JK |
12 | \0 (fn ([S] (get-in S [:memory arg])) |
13 | ([_ _] arg)) | |
c0464c3a | 14 | \1 (constantly arg) |
cce51437 JK |
15 | \2 (fn ([S] (get-in S [:memory (+ arg (:relctr S))])) |
16 | ([S _] (+ arg (:relctr S)))))) | |
c0464c3a JK |
17 | with-flags (fn [f] |
18 | (fn [S & args] | |
19 | (apply f S (map apply-flag flags args))))] | |
20 | (with-flags | |
21 | (case op | |
22 | [\0 \1] (fn [S a b c] ; ADD | |
23 | (-> S | |
cce51437 | 24 | (assoc-in [:memory (c S 0)] (+' (a S) (b S))) |
c0464c3a JK |
25 | (update :ctr + 4))) |
26 | [\0 \2] (fn [S a b c] ; MULT | |
27 | (-> S | |
cce51437 | 28 | (assoc-in [:memory (c S 0)] (*' (a S) (b S))) |
c0464c3a JK |
29 | (update :ctr + 4))) |
30 | [\0 \3] (fn [S a _ _] ; IN | |
31 | (-> S | |
cce51437 | 32 | (assoc-in [:memory (a S 0)] (first (:input S))) |
c0464c3a JK |
33 | (update :input subvec 1) |
34 | (update :ctr + 2))) | |
35 | [\0 \4] (fn [S a _ _] ; OUT | |
36 | (-> S | |
cce51437 | 37 | (update :output conj (get-in S [:memory (a S 0)])) |
c0464c3a JK |
38 | (update :ctr + 2))) |
39 | [\0 \5] (fn [S a b _] ; BNEQ | |
40 | (update S :ctr (if (not= (a S) 0) (constantly (b S)) #(+ % 3)))) | |
41 | [\0 \6] (fn [S a b _] ; BEQ | |
42 | (update S :ctr (if (= (a S) 0) (constantly (b S)) #(+ % 3)))) | |
43 | [\0 \7] (fn [S a b c] ; SLT | |
44 | (-> S | |
cce51437 | 45 | (assoc-in [:memory (c S 0)] (if (< (a S) (b S)) 1 0)) |
c0464c3a JK |
46 | (update :ctr + 4))) |
47 | [\0 \8] (fn [S a b c] ; SEQ | |
48 | (-> S | |
cce51437 | 49 | (assoc-in [:memory (c S 0)] (if (= (a S) (b S)) 1 0)) |
c0464c3a JK |
50 | (update :ctr + 4))) |
51 | [\0 \9] (fn [S a _ _] ; SREL | |
52 | (-> S | |
53 | (update :relctr + (a S)) | |
54 | (update :ctr + 2))) | |
55 | [\9 \9] (fn [S _ _ _] ; EXIT | |
56 | (assoc S :exit 1)))))) | |
57 | ||
58 | (defn- perform-operation [{:keys [memory ctr] :as state}] | |
59 | (let [operation (decode-op (memory ctr)) | |
60 | args (map memory [(+ 1 ctr) (+ 2 ctr) (+ 3 ctr)])] | |
61 | (apply operation state args))) | |
62 | ||
63 | (defn build-state | |
64 | ([program] | |
65 | (let [memory (into {} (map-indexed #(vector %1 %2) program))] | |
66 | {:memory memory :ctr 0 :input [] :output [] :relctr 0})) | |
67 | ([program settings] | |
68 | (merge (build-state program) settings))) | |
69 | ||
70 | (defn intcode [{:as state :keys [memory output]}] | |
71 | (cond ; quit if :exit, step and return state if :step, else loop | |
72 | (get state :exit) {:memory memory :output output} | |
73 | (get state :step) (perform-operation state) | |
74 | :else (recur (perform-operation state)))) |