2023: Day 5, part 1

2023/day5/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "day5"
+version = "0.1.0"

2023/day5/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "day5"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

2023/day5/src/main.rs

@@ -0,0 +1,119 @@
+use std::collections::HashMap;
+use std::ops::Range;
+use std::{env, fs};
+
+type BoxError = Box<dyn std::error::Error>;
+
+#[derive(Debug)]
+struct Map {
+    source: String,
+    dest: String,
+    mappings: Vec<MapRange>,
+}
+
+#[derive(Debug)]
+struct MapRange {
+    destination_range_start: usize,
+    source_range_start: usize,
+    length: usize,
+}
+
+fn main() -> Result<(), BoxError> {
+    let input_path = env::args_os()
+        .skip(1)
+        .next()
+        .ok_or("missing input file path")?;
+    let input = fs::read_to_string(input_path)?;
+    let mut chunks = input.split("\n\n");
+    let seeds_text = chunks.next().ok_or("missing seeds")?;
+    if !seeds_text.starts_with("seeds: ") {
+        return Err("seeds text does not start with expected prefix".into());
+    }
+    let seeds = seeds_text
+        .split_ascii_whitespace()
+        .skip(1)
+        .map(|text| text.parse::<usize>())
+        .collect::<Result<Vec<_>, _>>()?;
+    let mut maps = HashMap::new();
+    for map_text in chunks {
+        let map = read_map(map_text)?;
+        maps.insert(map.source.clone(), map);
+    }
+
+    // chase the seed ids through the maps
+    let locations = seeds
+        .iter()
+        .copied()
+        .map(|seed| {
+            let mut map = &maps["seed"];
+            let mut id = seed;
+            while map.dest != "location" {
+                id = map.lookup(id);
+                map = &maps[&map.dest];
+            }
+            map.lookup(id)
+        })
+        .collect::<Vec<_>>();
+
+    println!(
+        "Part 1: {}",
+        locations.iter().min().ok_or("no min location")?
+    );
+
+    Ok(())
+}
+
+fn read_map(input: &str) -> Result<Map, BoxError> {
+    let mut lines = input.lines();
+    let title = lines.next().ok_or("map missing title")?;
+    let (from_to, _) = title.split_once(' ').ok_or("unable to split title")?;
+    let mut words = from_to.split('-');
+    let source = words.next().ok_or("title missing source")?;
+    let _to = words.next();
+    let destination = words.next().ok_or("title missing destination")?;
+
+    let mut mappings = Vec::new();
+    for line in lines {
+        match line
+            .split_ascii_whitespace()
+            .map(|part| part.parse::<usize>())
+            .collect::<Result<Vec<_>, _>>()?
+            .as_slice()
+        {
+            &[destination_range_start, source_range_start, length] => mappings.push(MapRange {
+                destination_range_start,
+                source_range_start,
+                length,
+            }),
+            _ => return Err(format!("unable to parse '{}'", line).into()),
+        }
+    }
+
+    Ok(Map {
+        source: source.to_owned(),
+        dest: destination.to_owned(),
+        mappings,
+    })
+}
+
+impl Map {
+    fn lookup(&self, id: usize) -> usize {
+        self.mappings
+            .iter()
+            .find_map(|range| range.map(id))
+            .unwrap_or(id)
+    }
+}
+
+impl MapRange {
+    fn map(&self, id: usize) -> Option<usize> {
+        self.source_range().contains(&id).then(|| {
+            let offset = id - self.source_range_start;
+            self.destination_range_start + offset
+        })
+    }
+
+    fn source_range(&self) -> Range<usize> {
+        self.source_range_start..self.source_range_start + self.length
+    }
+}

2023/input/day5.sample

@@ -0,0 +1,33 @@
+seeds: 79 14 55 13
+
+seed-to-soil map:
+50 98 2
+52 50 48
+
+soil-to-fertilizer map:
+0 15 37
+37 52 2
+39 0 15
+
+fertilizer-to-water map:
+49 53 8
+0 11 42
+42 0 7
+57 7 4
+
+water-to-light map:
+88 18 7
+18 25 70
+
+light-to-temperature map:
+45 77 23
+81 45 19
+68 64 13
+
+temperature-to-humidity map:
+0 69 1
+1 0 69
+
+humidity-to-location map:
+60 56 37
+56 93 4

2023/input/day5.txt

@@ -0,0 +1,250 @@
+seeds: 28965817 302170009 1752849261 48290258 804904201 243492043 2150339939 385349830 1267802202 350474859 2566296746 17565716 3543571814 291402104 447111316 279196488 3227221259 47952959 1828835733 9607836
+
+seed-to-soil map:
+3680121696 1920754815 614845600
+1920754815 3846369604 448597692
+193356576 570761634 505124585
+2369352507 2535600415 31531965
+2400884472 2567132380 1279237224
+0 459278395 111483239
+698481161 97868205 361410190
+1059891351 0 15994868
+111483239 15994868 81873337
+
+soil-to-fertilizer map:
+1633669237 1273301814 72865265
+2398515176 2671190790 99210785
+2397916384 3018946373 598792
+4034325916 3061716397 20017393
+3298612516 3793795301 14249501
+4030007411 3051046904 2833129
+1906984482 224872691 14620134
+864506893 1590633724 149044542
+1029530319 442871336 36727018
+1921604616 770934113 68546178
+3560536321 3114405501 28822192
+1019762634 1263534129 9767685
+3852235341 3579014714 60339892
+2385228698 1577946038 12687686
+2234322470 239492825 150906228
+0 170310676 54562015
+3208946111 3808044802 89666405
+1209615399 839480291 424053838
+4032840540 4041982568 1485376
+2497725961 2174737461 293042810
+2002543511 1346167079 231778959
+3312862017 3475611771 103402943
+318739997 1739678266 354749094
+1013551435 3012735174 6211199
+4014277153 4160859076 15730258
+3589358513 3143227693 230682158
+1990150794 2467780271 12392717
+3051046904 3081733790 32671711
+3820040671 3761600631 32194670
+148429321 0 170310676
+673489091 2480172988 191017802
+1066257337 627576051 143358062
+2790768771 2770401575 242333599
+3091554979 4043467944 117391132
+3416264960 3897711207 144271361
+3912575233 3373909851 101701920
+4072291714 3639354606 104297620
+3083718615 3053880033 7836364
+54562015 3019545165 13557205
+1759006785 479598354 147977697
+68119220 2094427360 80310101
+1706534502 390399053 52472283
+4054343309 3743652226 17948405
+
+fertilizer-to-water map:
+0 1095885172 129797665
+2661548513 1044284418 17872363
+3282164642 3678907615 214830258
+1440687421 2218635146 325889720
+3496994900 4208791298 25912548
+3253828209 4136945159 5561683
+1797056017 864689597 109403664
+3259389892 4186016548 22774750
+2578517508 1225682837 83031005
+3193832718 3618912124 59995491
+3695649169 3214450646 211194594
+820325042 974093261 70191157
+1284591017 1074888739 20996433
+2929761569 3893737873 85668135
+1305587450 2605461705 73959171
+2168339930 1062156781 12731958
+2465234843 2135490203 52666067
+3522907448 4108091872 882860
+3523790308 4255675252 39292044
+2517900910 1308713842 60616598
+3563082352 3176039879 38410767
+3015429704 3979406008 128685864
+1913427402 2131043562 4446641
+2235159285 1419841841 190190495
+3673886186 4108974732 21762983
+891504291 1610032336 393086726
+3927815169 3425645240 193266884
+4121082053 3002154636 173885243
+2084864581 2004107154 83475349
+1917874043 557612753 69524983
+890516199 2003119062 988092
+766355924 2551492587 53969118
+1379546621 0 61140800
+3187625274 4130737715 6207444
+528804063 627137736 237551861
+1987399026 230411125 97465555
+1906459681 2544524866 6967721
+2184647884 1369330440 50511401
+2425349780 2091158499 39885063
+2181071888 2087582503 3575996
+3144115568 4142506842 43509706
+1766577141 2188156270 30478876
+359533738 61140800 169270325
+129797665 327876680 229736073
+3906843763 4234703846 20971406
+3601493119 2929761569 72393067
+
+water-to-light map:
+2375927917 1595026882 126334140
+1307603095 818620477 43777869
+2050676589 1855896418 112224406
+3618302244 2909504698 119958941
+3078570200 3088215627 6211083
+3084781283 3094426710 141266337
+524666822 53020621 149058240
+673725062 862398346 147671362
+2364320682 2577001713 11607235
+1941578413 1584221500 10805382
+2162900995 2536766467 40235246
+162015400 237365123 4480592
+821396424 241845715 141336168
+166495992 1138498800 212882164
+4277433486 4220367555 17533810
+3226047620 2229635217 307131250
+2909428734 1968120824 34606070
+1885573816 3954749082 56004597
+2711875933 2868267590 41237108
+0 726306378 92314099
+2944034804 1721361022 134535396
+1584221500 3392008740 301352316
+962732592 34415039 18605582
+2235705153 2101019688 128615529
+4252936467 4237901365 24497019
+92314099 202078861 35286262
+981338174 400041457 326264921
+379378156 1010069708 128429092
+3591930858 3693361056 26371386
+3785017329 3719732442 235016640
+2502262057 4010753679 209613876
+3533178870 3029463639 58751988
+3738261185 2821511446 46756144
+4020033969 2806534555 14976891
+1952383795 2002726894 98292794
+127600361 0 34415039
+2753113041 3235693047 156315693
+507807248 383181883 16859574
+2203136241 4262398384 32568912
+4035010860 2588608948 217925607
+
+light-to-temperature map:
+2137189745 1335050925 100355790
+639139367 2440321747 987829
+1663612748 1778059435 153830272
+1122754252 1950103191 82536600
+1929621334 1199531530 135519395
+1286703174 2032639791 207137687
+245313533 981575774 217955756
+2597564380 2824691125 293777778
+895004176 331442633 25226735
+1493840861 236388681 616173
+1494457034 764560381 107637728
+1817443020 1435406715 112178314
+1205290852 356669368 33552643
+474799702 0 164339665
+2341054397 2260378974 100255179
+1043066658 2360634153 79687594
+125852143 390222011 119461390
+3924383937 3130691909 13614218
+2467721984 3747288823 76649669
+2065140729 164339665 72049016
+920230911 1673437172 104622263
+640127196 509683401 254876980
+1024853174 1931889707 18213484
+2331983314 2251307891 9071083
+2237545535 237004854 94437779
+3912160931 3118468903 12223006
+1238843495 933716095 47859679
+3326002417 3517222025 230066798
+3556069215 3144306127 241363224
+3797432439 4180238804 114728492
+1602094762 872198109 61517986
+2544371653 4127046077 53192727
+2891342158 3823938492 303107585
+463269289 2239777478 11530413
+3194449743 3385669351 131552674
+3937998155 2467721984 356969141
+0 1547585029 125852143
+
+temperature-to-humidity map:
+2687600833 2313887435 187105587
+3281196981 2291603041 22284394
+1771250828 1899269239 314167725
+784031720 478456148 306959384
+2605226464 1771250828 58348072
+2085418553 3793564740 111907603
+1090991104 785415532 575136195
+3437652344 1829598900 69670339
+2874706420 2500993022 389039942
+3303481375 3905472343 134170969
+305575572 0 478456148
+3263746362 2890032964 17450619
+2527060387 2213436964 78166077
+2428623843 3695128196 98436544
+2663574536 4270940999 24026297
+3507322683 2907483583 787644613
+2197326156 4039643312 231297687
+0 1360551727 305575572
+
+humidity-to-location map:
+1919184105 1156349110 51114849
+4031284281 3411510751 25609498
+0 171183359 79004094
+1253227229 2072782209 122019778
+4056893779 3437120249 136289693
+3402931364 4156827458 101778985
+84557792 1207463959 134801591
+635909965 1371746366 266495395
+4029464617 4127764171 1819664
+4193183472 2857352625 101783824
+1375247007 2200355685 41445634
+1996492203 0 171183359
+3601595563 3699895117 427869054
+2218993186 1133540977 22808133
+3217192942 2959136449 140385316
+2987922009 4258606443 9236491
+2628749093 2543337773 86365212
+2167675562 369831582 51317624
+3504710349 2446452559 96885214
+902405360 421149206 108869392
+3357578258 2811999519 45353106
+1196458443 1638241761 56768786
+1178674352 693035436 17784091
+1970298954 530018598 26193249
+2868723842 3099521765 91954544
+1522874936 895259169 18612073
+2841599480 4267842934 27124362
+1880563756 1695010547 38620349
+1011274752 913871242 137918784
+219359383 556211847 136823589
+1785350971 250187453 95212785
+2960678386 4129583835 27243623
+540622614 1977494858 95287351
+356182972 710819527 184439642
+1498443592 345400238 24431344
+1416692641 1051790026 81750951
+1541487009 1733630896 243863962
+79004094 2194801987 5553698
+1149193536 1342265550 29480816
+2997158500 3191476309 220034442
+2715114305 3573409942 126485175
+2446452559 2629702985 182296534