day7.js

describe.only(`Day 7`, () => {
  function parse (string) {
    const a = string.split(' ');
    let input, output, opt;
    output = a[a.length - 1];
    if (a[0] === 'NOT') {
      opt = 'NOT';
      input = [a[1]];
    } else {
      switch (a[1]) {
        case 'AND':
        case 'OR':
        case 'LSHIFT':
        case 'RSHIFT':
          input = [a[0], a[2]];
          opt = [a[1]];
          break;
        default:
          input = [a[0]];
          opt = 'NONE';
          break;
      }
    }

    return {
      input, output, opt, string
    }
  };

  function build (inp) {
    const c = new Map();
    inp.forEach(i => {
      const parsed = parse(i);
      c.set(parsed.output, parsed);
    });

    return c;
  };

  const OPTS = {
    NOT: (v) => ~ (v >>> 0),
    NONE: (v) => v,
    AND:(a, b) => a & b,
    OR: (a, b) => a | b,
    LSHIFT: (a, b) => a << b,
    RSHIFT: (a, b) => a >> b,
  }

  function _evaluate (circut, wire) {
    const w = circut.get(wire);

    // HACK: if the wire isn't in the map it is a literal value
    // (assuming no invalid inputs)
    if (w === undefined) return wire;

    const opt = OPTS[w.opt];
    if  (opt === undefined) throw new Error(w.opt);
    return opt(...w.input.map(i => evaluate(circut, i)))
      & 65535; // Cast down to 16 bit
  };

  // Boy this is bad :(
  const memo = new Map();
  function evaluate (circut, w) {
    const c_memo = (memo.has(circut))
      ? memo.get(circut) : new Map();
    memo.set(circut, c_memo);

    if (c_memo.has(w)) return c_memo.get(w);
    c_memo.set(w, _evaluate(circut, w));
    return c_memo.get(w);
  }

  describe('Part 1', () => {
    describe('example', () => {
      const examples = new Map([
        ['d', 72],
        ['e', 507],
        ['f', 492],
        ['g', 114],
        ['h', 65412],
        ['i', 65079],
        ['x', 123],
        ['y', 456],
      ]);

      examples.forEach((v, k) => {
        const circut = build(example());
        it(`should evaluate ${k} to ${v}`, () => {
          evaluate(circut, k).should.eql(v);
        });
      });

      const wire = 'a';
      const output = 16076;
      it (`should evaluate '${wire}' to ${output}`, () => {
        evaluate(build(input()), wire).should.eql(output);
      });
    });
  });

  describe('Part 2', () => {
    const wire_a = 16076; // Answer from part 1;
    const circut = build(input());

    circut.set('b', {
      input: [ String(wire_a) ],
      output: 'b',
      opt: 'NONE',
    });

    const wire = 'a';
    const output = 2797;
    it (`should evaluate 'b' to ${wire_a}`, () => {
      evaluate(circut, 'b').should.eql(wire_a);
    });
    it (`should evaluate '${wire}' to ${output}`, () => {
      evaluate(circut, wire).should.eql(output);
    });
  });


});

function example () {
  return `
  123 -> x
  456 -> y
  x AND y -> d
  x OR y -> e
  x LSHIFT 2 -> f
  y RSHIFT 2 -> g
  NOT x -> h
  NOT y -> i`.split('\n').map(a => a.trim());
}

function input () {
  return `
    lf AND lq -> ls
    iu RSHIFT 1 -> jn
    bo OR bu -> bv
    gj RSHIFT 1 -> hc
    et RSHIFT 2 -> eu
    bv AND bx -> by
    is OR it -> iu
    b OR n -> o
    gf OR ge -> gg
    NOT kt -> ku
    ea AND eb -> ed
    kl OR kr -> ks
    hi AND hk -> hl
    au AND av -> ax
    lf RSHIFT 2 -> lg
    dd RSHIFT 3 -> df
    eu AND fa -> fc
    df AND dg -> di
    ip LSHIFT 15 -> it
    NOT el -> em
    et OR fe -> ff
    fj LSHIFT 15 -> fn
    t OR s -> u
    ly OR lz -> ma
    ko AND kq -> kr
    NOT fx -> fy
    et RSHIFT 1 -> fm
    eu OR fa -> fb
    dd RSHIFT 2 -> de
    NOT go -> gp
    kb AND kd -> ke
    hg OR hh -> hi
    jm LSHIFT 1 -> kg
    NOT cn -> co
    jp RSHIFT 2 -> jq
    jp RSHIFT 5 -> js
    1 AND io -> ip
    eo LSHIFT 15 -> es
    1 AND jj -> jk
    g AND i -> j
    ci RSHIFT 3 -> ck
    gn AND gp -> gq
    fs AND fu -> fv
    lj AND ll -> lm
    jk LSHIFT 15 -> jo
    iu RSHIFT 3 -> iw
    NOT ii -> ij
    1 AND cc -> cd
    bn RSHIFT 3 -> bp
    NOT gw -> gx
    NOT ft -> fu
    jn OR jo -> jp
    iv OR jb -> jc
    hv OR hu -> hw
    19138 -> b
    gj RSHIFT 5 -> gm
    hq AND hs -> ht
    dy RSHIFT 1 -> er
    ao OR an -> ap
    ld OR le -> lf
    bk LSHIFT 1 -> ce
    bz AND cb -> cc
    bi LSHIFT 15 -> bm
    il AND in -> io
    af AND ah -> ai
    as RSHIFT 1 -> bl
    lf RSHIFT 3 -> lh
    er OR es -> et
    NOT ax -> ay
    ci RSHIFT 1 -> db
    et AND fe -> fg
    lg OR lm -> ln
    k AND m -> n
    hz RSHIFT 2 -> ia
    kh LSHIFT 1 -> lb
    NOT ey -> ez
    NOT di -> dj
    dz OR ef -> eg
    lx -> a
    NOT iz -> ja
    gz LSHIFT 15 -> hd
    ce OR cd -> cf
    fq AND fr -> ft
    at AND az -> bb
    ha OR gz -> hb
    fp AND fv -> fx
    NOT gb -> gc
    ia AND ig -> ii
    gl OR gm -> gn
    0 -> c
    NOT ca -> cb
    bn RSHIFT 1 -> cg
    c LSHIFT 1 -> t
    iw OR ix -> iy
    kg OR kf -> kh
    dy OR ej -> ek
    km AND kn -> kp
    NOT fc -> fd
    hz RSHIFT 3 -> ib
    NOT dq -> dr
    NOT fg -> fh
    dy RSHIFT 2 -> dz
    kk RSHIFT 2 -> kl
    1 AND fi -> fj
    NOT hr -> hs
    jp RSHIFT 1 -> ki
    bl OR bm -> bn
    1 AND gy -> gz
    gr AND gt -> gu
    db OR dc -> dd
    de OR dk -> dl
    as RSHIFT 5 -> av
    lf RSHIFT 5 -> li
    hm AND ho -> hp
    cg OR ch -> ci
    gj AND gu -> gw
    ge LSHIFT 15 -> gi
    e OR f -> g
    fp OR fv -> fw
    fb AND fd -> fe
    cd LSHIFT 15 -> ch
    b RSHIFT 1 -> v
    at OR az -> ba
    bn RSHIFT 2 -> bo
    lh AND li -> lk
    dl AND dn -> do
    eg AND ei -> ej
    ex AND ez -> fa
    NOT kp -> kq
    NOT lk -> ll
    x AND ai -> ak
    jp OR ka -> kb
    NOT jd -> je
    iy AND ja -> jb
    jp RSHIFT 3 -> jr
    fo OR fz -> ga
    df OR dg -> dh
    gj RSHIFT 2 -> gk
    gj OR gu -> gv
    NOT jh -> ji
    ap LSHIFT 1 -> bj
    NOT ls -> lt
    ir LSHIFT 1 -> jl
    bn AND by -> ca
    lv LSHIFT 15 -> lz
    ba AND bc -> bd
    cy LSHIFT 15 -> dc
    ln AND lp -> lq
    x RSHIFT 1 -> aq
    gk OR gq -> gr
    NOT kx -> ky
    jg AND ji -> jj
    bn OR by -> bz
    fl LSHIFT 1 -> gf
    bp OR bq -> br
    he OR hp -> hq
    et RSHIFT 5 -> ew
    iu RSHIFT 2 -> iv
    gl AND gm -> go
    x OR ai -> aj
    hc OR hd -> he
    lg AND lm -> lo
    lh OR li -> lj
    da LSHIFT 1 -> du
    fo RSHIFT 2 -> fp
    gk AND gq -> gs
    bj OR bi -> bk
    lf OR lq -> lr
    cj AND cp -> cr
    hu LSHIFT 15 -> hy
    1 AND bh -> bi
    fo RSHIFT 3 -> fq
    NOT lo -> lp
    hw LSHIFT 1 -> iq
    dd RSHIFT 1 -> dw
    dt LSHIFT 15 -> dx
    dy AND ej -> el
    an LSHIFT 15 -> ar
    aq OR ar -> as
    1 AND r -> s
    fw AND fy -> fz
    NOT im -> in
    et RSHIFT 3 -> ev
    1 AND ds -> dt
    ec AND ee -> ef
    NOT ak -> al
    jl OR jk -> jm
    1 AND en -> eo
    lb OR la -> lc
    iu AND jf -> jh
    iu RSHIFT 5 -> ix
    bo AND bu -> bw
    cz OR cy -> da
    iv AND jb -> jd
    iw AND ix -> iz
    lf RSHIFT 1 -> ly
    iu OR jf -> jg
    NOT dm -> dn
    lw OR lv -> lx
    gg LSHIFT 1 -> ha
    lr AND lt -> lu
    fm OR fn -> fo
    he RSHIFT 3 -> hg
    aj AND al -> am
    1 AND kz -> la
    dy RSHIFT 5 -> eb
    jc AND je -> jf
    cm AND co -> cp
    gv AND gx -> gy
    ev OR ew -> ex
    jp AND ka -> kc
    fk OR fj -> fl
    dy RSHIFT 3 -> ea
    NOT bs -> bt
    NOT ag -> ah
    dz AND ef -> eh
    cf LSHIFT 1 -> cz
    NOT cv -> cw
    1 AND cx -> cy
    de AND dk -> dm
    ck AND cl -> cn
    x RSHIFT 5 -> aa
    dv LSHIFT 1 -> ep
    he RSHIFT 2 -> hf
    NOT bw -> bx
    ck OR cl -> cm
    bp AND bq -> bs
    as OR bd -> be
    he AND hp -> hr
    ev AND ew -> ey
    1 AND lu -> lv
    kk RSHIFT 3 -> km
    b AND n -> p
    NOT kc -> kd
    lc LSHIFT 1 -> lw
    km OR kn -> ko
    id AND if -> ig
    ih AND ij -> ik
    jr AND js -> ju
    ci RSHIFT 5 -> cl
    hz RSHIFT 1 -> is
    1 AND ke -> kf
    NOT gs -> gt
    aw AND ay -> az
    x RSHIFT 2 -> y
    ab AND ad -> ae
    ff AND fh -> fi
    ci AND ct -> cv
    eq LSHIFT 1 -> fk
    gj RSHIFT 3 -> gl
    u LSHIFT 1 -> ao
    NOT bb -> bc
    NOT hj -> hk
    kw AND ky -> kz
    as AND bd -> bf
    dw OR dx -> dy
    br AND bt -> bu
    kk AND kv -> kx
    ep OR eo -> eq
    he RSHIFT 1 -> hx
    ki OR kj -> kk
    NOT ju -> jv
    ek AND em -> en
    kk RSHIFT 5 -> kn
    NOT eh -> ei
    hx OR hy -> hz
    ea OR eb -> ec
    s LSHIFT 15 -> w
    fo RSHIFT 1 -> gh
    kk OR kv -> kw
    bn RSHIFT 5 -> bq
    NOT ed -> ee
    1 AND ht -> hu
    cu AND cw -> cx
    b RSHIFT 5 -> f
    kl AND kr -> kt
    iq OR ip -> ir
    ci RSHIFT 2 -> cj
    cj OR cp -> cq
    o AND q -> r
    dd RSHIFT 5 -> dg
    b RSHIFT 2 -> d
    ks AND ku -> kv
    b RSHIFT 3 -> e
    d OR j -> k
    NOT p -> q
    NOT cr -> cs
    du OR dt -> dv
    kf LSHIFT 15 -> kj
    NOT ac -> ad
    fo RSHIFT 5 -> fr
    hz OR ik -> il
    jx AND jz -> ka
    gh OR gi -> gj
    kk RSHIFT 1 -> ld
    hz RSHIFT 5 -> ic
    as RSHIFT 2 -> at
    NOT jy -> jz
    1 AND am -> an
    ci OR ct -> cu
    hg AND hh -> hj
    jq OR jw -> jx
    v OR w -> x
    la LSHIFT 15 -> le
    dh AND dj -> dk
    dp AND dr -> ds
    jq AND jw -> jy
    au OR av -> aw
    NOT bf -> bg
    z OR aa -> ab
    ga AND gc -> gd
    hz AND ik -> im
    jt AND jv -> jw
    z AND aa -> ac
    jr OR js -> jt
    hb LSHIFT 1 -> hv
    hf OR hl -> hm
    ib OR ic -> id
    fq OR fr -> fs
    cq AND cs -> ct
    ia OR ig -> ih
    dd OR do -> dp
    d AND j -> l
    ib AND ic -> ie
    as RSHIFT 3 -> au
    be AND bg -> bh
    dd AND do -> dq
    NOT l -> m
    1 AND gd -> ge
    y AND ae -> ag
    fo AND fz -> gb
    NOT ie -> if
    e AND f -> h
    x RSHIFT 3 -> z
    y OR ae -> af
    hf AND hl -> hn
    NOT h -> i
    NOT hn -> ho
    he RSHIFT 5 -> hh
    `.split('\n').map(a => a.trim());
}