~nilium/aoc2020

25414e8c11901aa1826ed45c86bd00d598dd4ae8 — Noel Cower 3 years ago 33e9485 
Add day 9

This one was pretty boring and just involves a combination and
a sliding window. Since I had the combination type from day one, I just
reused that for part one. For part 2, the sliding window is easy enough
to do in a for loop (though it'd be fancier with an iterator-ish type).

Got to learn about std.sort, so time well spent.
patch browse .tar.gz 
3 files changed, 1059 insertions(+), 0 deletions(-)

M build.zig
A day9/src/input.zig
A day9/src/main.zig

M build.zig => build.zig +1 -0
@@ 26,6 26,7 @@ const days = [_]Pkg{
    newPkg("day6"),
    newPkg("day7"),
    newPkg("day8"),
    newPkg("day9"),
};

fn dayBuild(day: Pkg, b: *Builder, target: Target, mode: std.builtin.Mode) void {


A day9/src/input.zig => day9/src/input.zig +1002 -0
@@ 0,0 1,1002 @@
pub const Input = [_]usize{
    19,
    30,
    13,
    31,
    42,
    41,
    44,
    34,
    39,
    6,
    47,
    50,
    36,
    33,
    32,
    15,
    43,
    8,
    26,
    24,
    48,
    5,
    3,
    10,
    1,
    20,
    4,
    7,
    9,
    22,
    11,
    12,
    16,
    13,
    14,
    17,
    6,
    28,
    57,
    18,
    19,
    15,
    21,
    8,
    23,
    24,
    25,
    5,
    26,
    10,
    27,
    20,
    29,
    30,
    33,
    22,
    43,
    78,
    31,
    32,
    41,
    11,
    13,
    16,
    56,
    28,
    37,
    40,
    15,
    35,
    18,
    38,
    21,
    23,
    24,
    70,
    34,
    26,
    45,
    27,
    102,
    29,
    33,
    36,
    108,
    31,
    32,
    39,
    41,
    42,
    46,
    78,
    50,
    56,
    44,
    47,
    48,
    152,
    104,
    84,
    64,
    68,
    53,
    58,
    136,
    60,
    61,
    67,
    106,
    71,
    63,
    73,
    80,
    88,
    108,
    90,
    97,
    114,
    148,
    143,
    118,
    198,
    133,
    111,
    121,
    117,
    113,
    161,
    124,
    123,
    131,
    256,
    130,
    134,
    136,
    222,
    153,
    185,
    178,
    233,
    203,
    208,
    232,
    234,
    245,
    224,
    237,
    228,
    274,
    244,
    230,
    236,
    276,
    267,
    253,
    398,
    264,
    266,
    356,
    289,
    397,
    661,
    436,
    381,
    411,
    440,
    609,
    452,
    458,
    525,
    889,
    496,
    464,
    666,
    466,
    565,
    500,
    517,
    520,
    519,
    530,
    553,
    702,
    686,
    893,
    792,
    894,
    957,
    1132,
    851,
    892,
    1453,
    982,
    1478,
    1409,
    985,
    930,
    964,
    1422,
    966,
    1017,
    1019,
    1036,
    1221,
    1818,
    1232,
    1239,
    2053,
    1537,
    1643,
    1684,
    1912,
    1743,
    1781,
    1815,
    1822,
    1894,
    2249,
    1947,
    3065,
    1896,
    1930,
    2036,
    2460,
    2779,
    2923,
    2471,
    4513,
    2453,
    2769,
    2882,
    3020,
    3590,
    3427,
    5018,
    3728,
    3524,
    3558,
    3596,
    4924,
    3966,
    4699,
    4720,
    8223,
    4918,
    11951,
    6043,
    4496,
    4913,
    5232,
    8147,
    5222,
    5335,
    8471,
    5651,
    8054,
    6447,
    6951,
    14918,
    7082,
    13398,
    10145,
    8462,
    7562,
    9414,
    8665,
    9195,
    9638,
    10150,
    9409,
    9718,
    9728,
    9831,
    10567,
    10454,
    10557,
    10873,
    10986,
    16033,
    12098,
    19142,
    17200,
    16024,
    17860,
    14644,
    18916,
    16227,
    16757,
    25864,
    18074,
    19549,
    18833,
    19047,
    19559,
    19127,
    20285,
    29483,
    21430,
    21011,
    28855,
    54719,
    36318,
    31647,
    31014,
    50789,
    51299,
    36987,
    30668,
    31401,
    35060,
    32984,
    34301,
    34831,
    36907,
    37121,
    37880,
    56713,
    38174,
    40989,
    81803,
    41296,
    42441,
    49866,
    69527,
    63048,
    61682,
    62415,
    62661,
    65499,
    62069,
    63652,
    65702,
    64385,
    67285,
    70105,
    78417,
    69132,
    71738,
    94593,
    75001,
    76054,
    100243,
    131793,
    83430,
    105681,
    83737,
    104123,
    111548,
    142286,
    128117,
    123751,
    142069,
    124730,
    125721,
    126454,
    130087,
    131670,
    195489,
    136417,
    139237,
    217287,
    170647,
    155168,
    151055,
    158431,
    260168,
    167167,
    211547,
    187553,
    187860,
    258124,
    234210,
    236278,
    248481,
    249472,
    303584,
    250451,
    285255,
    252175,
    286838,
    266504,
    268087,
    474698,
    294848,
    329078,
    306223,
    419342,
    318222,
    309486,
    378714,
    535706,
    354720,
    375413,
    421763,
    422070,
    470488,
    519465,
    484759,
    497953,
    551759,
    539013,
    516955,
    575990,
    534591,
    649568,
    954704,
    577573,
    601071,
    604334,
    615709,
    624445,
    733434,
    627708,
    664206,
    839479,
    976484,
    776483,
    797176,
    1090772,
    892558,
    1331767,
    1144663,
    982712,
    1014908,
    1215965,
    1404191,
    1334505,
    1110581,
    1380817,
    1178644,
    1181907,
    2346675,
    1803089,
    1220043,
    1573659,
    1252153,
    1291914,
    2583920,
    1615962,
    1887064,
    2192449,
    2350142,
    1689734,
    2947752,
    1875270,
    2159571,
    1997620,
    3303030,
    2125489,
    2289225,
    3291255,
    4594944,
    2292488,
    3127423,
    2360551,
    4233739,
    2825812,
    4045855,
    2511957,
    6522964,
    2544067,
    2907876,
    3305696,
    4669556,
    9825994,
    3565004,
    3687354,
    3815223,
    4290108,
    3872890,
    4123109,
    4649776,
    4414714,
    4417977,
    6635066,
    4653039,
    4872508,
    10450289,
    4904618,
    5056024,
    5337769,
    5369879,
    5451943,
    5419833,
    5849763,
    6109071,
    7197984,
    7178586,
    8621028,
    11301695,
    7252358,
    8525929,
    8995617,
    8777508,
    7995999,
    8537823,
    12070492,
    8832691,
    16617027,
    9525547,
    11831625,
    10324451,
    9960642,
    22726098,
    10393793,
    14447560,
    10789712,
    10871776,
    16502864,
    11958834,
    13361429,
    15873386,
    17576809,
    16521928,
    15248357,
    15778287,
    16533822,
    17315331,
    16773507,
    16828690,
    20664316,
    18358238,
    18793333,
    19486189,
    24772011,
    20285093,
    30609544,
    20354435,
    21183505,
    21265569,
    42568378,
    27563219,
    27207191,
    29883357,
    32021864,
    28609786,
    31026644,
    31770285,
    31782179,
    32077047,
    32312109,
    33307329,
    45955516,
    39771282,
    36314879,
    40058902,
    39147768,
    51508053,
    39840624,
    60413337,
    69775569,
    41537940,
    67757554,
    42449074,
    53577678,
    62195466,
    54770410,
    55816977,
    58493143,
    59636430,
    60380071,
    62796929,
    63552464,
    72135949,
    64389156,
    88077739,
    72455097,
    82270395,
    78763953,
    97640911,
    78988392,
    158054248,
    81378564,
    82289698,
    117966834,
    83987014,
    130554483,
    141906825,
    173003557,
    108348088,
    121290072,
    185718650,
    114310120,
    118129573,
    160213688,
    255273952,
    126349393,
    164560093,
    136525105,
    136844253,
    151219050,
    154744795,
    195688684,
    157752345,
    160366956,
    161278090,
    163668262,
    196599818,
    208639091,
    192335102,
    198297134,
    226477661,
    234697481,
    222658208,
    232439693,
    416552042,
    250835225,
    387360330,
    244478966,
    262874498,
    314887312,
    263193646,
    273369358,
    321645046,
    288063303,
    567771092,
    451731565,
    402231311,
    318119301,
    324035218,
    485851854,
    356003364,
    388934920,
    406936225,
    556342527,
    420955342,
    449135869,
    510721511,
    467137174,
    495314191,
    507353464,
    764023181,
    393911906,
    532542269,
    526068144,
    578080958,
    561432661,
    591488659,
    909584775,
    676998223,
    642154519,
    674122665,
    680038582,
    739074643,
    1036789655,
    912345891,
    805139233,
    814867248,
    919980050,
    1446048194,
    1404898966,
    1684003231,
    1355511840,
    1068786125,
    2760410806,
    1036066425,
    926454175,
    1070910129,
    1255079181,
    1087500805,
    2035550422,
    1727213139,
    2715589004,
    1316277184,
    1678220944,
    1322193101,
    1586468556,
    2657378685,
    1544213876,
    1620006481,
    1717485124,
    2106976554,
    1734847298,
    1962520600,
    2242731359,
    2385063309,
    3926734590,
    3697367898,
    2546460656,
    1997364304,
    2248647276,
    2013954980,
    2631714681,
    2707507286,
    2403777989,
    2866406977,
    3617370785,
    3559008543,
    2638470285,
    2908661657,
    3057040399,
    4601254275,
    3164220357,
    7176379328,
    3337491605,
    3976475580,
    3732211602,
    3748802278,
    3959884904,
    5406951716,
    4246011580,
    5556372847,
    4262602256,
    4011319284,
    4401142293,
    6643033965,
    4417732969,
    5035492670,
    5923447376,
    5042248274,
    6246153262,
    5547131942,
    11470579318,
    5695510684,
    5965702056,
    6221260756,
    7086293883,
    6501711962,
    7313967185,
    9298094926,
    8791050552,
    16612062111,
    9436634963,
    9516257751,
    8412461577,
    8257330864,
    8273921540,
    8429052253,
    14394754309,
    8818875262,
    9453225639,
    9459981243,
    10077740944,
    25910157037,
    10589380216,
    11242642626,
    11512833998,
    13815679147,
    11661212740,
    19935134280,
    16702973793,
    13588005845,
    15292762514,
    18351662484,
    21590574942,
    16531252404,
    17790179291,
    27788297447,
    24943713981,
    16686383117,
    17076206126,
    17727147179,
    35987897981,
    18272100901,
    18278856505,
    27804888123,
    25249218585,
    20667121160,
    27275763333,
    21832022842,
    22755476624,
    34882914888,
    28364186533,
    29933313641,
    46156550607,
    30290979638,
    31860106746,
    31824014918,
    33217635521,
    33607458530,
    34258399583,
    54266754486,
    33762589243,
    34958484018,
    44881094249,
    55639949866,
    40110879347,
    36550957406,
    38939222061,
    41034333129,
    61038352576,
    42499144002,
    43422597784,
    89149669374,
    68565942548,
    65254620626,
    84991973596,
    58297500174,
    60224293279,
    75069363365,
    62114994556,
    69216883601,
    97073478574,
    90817711892,
    70313546649,
    68721073261,
    101054216617,
    71509441424,
    95996836594,
    115180242712,
    75490179467,
    76661836753,
    77585290535,
    79973555190,
    112143671045,
    85921741786,
    101720097958,
    162328099200,
    118521793453,
    170791267082,
    120412494730,
    122339287835,
    127018573435,
    146975383402,
    137937956862,
    131331878157,
    139034619910,
    140230514685,
    173582127129,
    141822988073,
    169775289878,
    211177079306,
    146999620891,
    152152016220,
    154247127288,
    153075470002,
    239162244480,
    157558845725,
    307322597290,
    187641839744,
    204443535239,
    233051976115,
    238934288183,
    253671165992,
    259447114640,
    329464827817,
    284407348159,
    518499676596,
    270366498067,
    406634103244,
    509528742547,
    279265134595,
    293305984687,
    288822608964,
    327334135603,
    476464448708,
    299151637111,
    300075090893,
    305227486222,
    552753099327,
    310634315727,
    443605779719,
    390610821840,
    392085374983,
    509671021461,
    437495511354,
    526357960802,
    492605454175,
    513118280632,
    529813612707,
    569518135178,
    610709406620,
    575593984289,
    549631632662,
    568087743559,
    604379123333,
    671350509578,
    598533470909,
    587974246075,
    1026096081370,
    599226728004,
    791757091286,
    1079189156639,
    996464498316,
    754240095446,
    748129827081,
    782696196823,
    828106333194,
    829580886337,
    930100965529,
    987127144016,
    1105407596996,
    1022419066882,
    1111651751541,
    1079445245369,
    1137605878737,
    1117719376221,
    1166621214468,
    1148165103571,
    1370670442898,
    1186507716984,
    1187200974079,
    1584438744391,
    1342214341521,
    1347356555085,
    1353466823450,
    1545997186732,
    1502369922527,
    1530826023904,
    2300771408427,
    2243013475733,
    1610802530017,
    2495521658656,
    1816708030353,
    1917228109545,
    2009546210898,
    3827452220124,
    2160024945619,
    2581815167896,
    2648545400125,
    2255325254958,
    2518835546469,
    2314786318039,
    2334672820555,
    2373708691063,
    2528722058505,
    2529415315600,
    2689570896606,
    2700823378535,
    3319077952880,
    2899464010182,
    3911573938444,
    3033195946431,
    3347534054257,
    3427510560370,
    3528030639562,
    3620348740915,
    3733936139898,
    3926774320443,
    4077253055164,
    4169571156517,
    4415350200577,
    5015609696574,
    4570111572997,
    4833621864508,
    8481685511441,
    4649459138594,
    6261447140998,
    4708381511618,
    7733085874690,
    5932659956613,
    5218986212206,
    11171256408047,
    5600287388717,
    6427494649744,
    11810338929854,
    6380730000688,
    6460706506801,
    6775044614627,
    7161446700268,
    8496885893440,
    8567558004406,
    9723991208192,
    8004027375607,
    8246824211681,
    9064809339171,
    13315307375949,
    9219570711591,
    9278493084615,
    9357840650212,
    9927367723824,
    9868445350800,
    17925398654618,
    10308668900335,
    10819273600923,
    13155774615315,
    11599716212894,
    11981017389405,
    15021868826308,
    16381017411859,
    12841436507489,
    20819286924485,
    17466394923272,
    13936491314895,
    19002484292807,
    25536207527789,
    16250851587288,
    20032660108527,
    17068836714778,
    17311633550852,
    25136792004720,
    18498063796206,
    24245160215230,
    19285208374036,
    21338858039617,
    23975048216238,
    22418989813817,
    23660710108412,
    21127942501258,
    22800290990328,
    24755490828209,
    28668552927672,
    27002886215713,
    26777927822384,
    32631868999147,
    29092288094777,
    30187342902183,
    39869127705106,
    31005328029673,
    49124948203304,
};


A day9/src/main.zig => day9/src/main.zig +56 -0
@@ 0,0 1,56 @@
const std = @import("std");
const Combination = @import("nil").combination.Combination;

const Combo25 = Combination(usize, 2);

const Error = error{
    SecretNotFound,
    WeaknessNotFound,
};

const usizeAsc = std.sort.asc(usize);

pub fn main() anyerror!void {
    // I didn't really feel like writing code to parse this. I could've, but
    // I just didn't.
    const input = @import("./input.zig").Input;

    // Part 1 -- Find a window of numbers where the last number is not the sum
    // of a combination of two numbers before it.
    var secret: usize = undefined;
    {
        var i: usize = 0;
        const window: usize = 26;
        secret = search: while ((i + window) < input.len) : (i += 1) {
            const prefix = input[i .. i + window - 1];
            const sum = input[i + window - 1];
            var combo = Combo25.init(prefix);
            while (combo.next()) |p| {
                if (p[0] + p[1] == sum) {
                    continue :search;
                }
            } else break sum;
        } else return Error.SecretNotFound;
        std.log.info("Secret = {}", .{secret});
    }

    // Part 2 -- Find a sliding window of numbers that sums to part 1's number,
    // then sum the min and max of that window.
    {
        var window: usize = 2;
        var minmax = search: while (window < input.len) : (window += 1) {
            var i: usize = 0;
            while ((i + window) < input.len) : (i += 1) {
                const prefix = input[i .. i + window];
                var sum: usize = 0;
                for (prefix) |p| sum += p;
                if (sum == secret) {
                    const min = std.sort.min(usize, prefix, {}, usizeAsc).?;
                    const max = std.sort.max(usize, prefix, {}, usizeAsc).?;
                    break :search min + max;
                }
            }
        } else return Error.WeaknessNotFound;
        std.log.info("Sum = {}", .{minmax});
    }
}