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