Day 8. rust-lang/rust#62208 when

Cargo.toml

@@ -12,11 +12,12 @@ members = [
     "aoc_4",
     "aoc_5",
     "aoc_6",
-    "aoc_7"
+    "aoc_7",
+    "aoc_8"
 ]
 
 
 [workspace.dependencies]
 anyhow = "1"
 criterion = "0.4.0"
-itertools = "0.10"
+itertools = "0.10"

aoc_8/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "aoc_8"
+version = "0.1.0"
+edition = "2021"
+
+[[bin]]
+name = "aoc_8"
+path = "src/main.rs"
+
+[lib]
+name = "aoc_8"
+path = "src/lib.rs"
+
+[dependencies]
+take-until = "0.1.0" # Needed, waiting for https://github.com/rust-lang/rust/issues/62208

aoc_8/input.txt

@@ -0,0 +1,99 @@
+222111121311033010320131232031301000043332012154435114414332231343214412243233401310320330011110110
+122212201111221321022211311332344223042233341324332523523451325341142120141122414312310331033122112
+012111111333222132312234104304231313255134131242541455235523145232422021413232302323121320032011100
+211112120020203103314110410023234421314251333452341121341453515343444003001233422242223302311322200
+201210231131221012402131143034554222213355322225431255115341554445545541340414012213010002022202002
+112200212013012331224041131431522545212335544414555455151514551355224111403003400100040011011022300
+011101003322133204344222231251351234321112111235521513115552341343112533431220123311340210102232210
+122031031210444124404433321415312412142152324266644622453522311421133335415423110130434110030001112
+231221010204100311040145313333451444115452246324454524453256552133145142211341204021224414110333023
+032311333241032133333455425531342135163445645454622552233433325553551212411421443333410023110233011
+033313120420341201102342315423553325433254625346435255555452263354534422523313343134424134302222233
+210122034100322230223332211251432356525226642452544226253323645335644545144314143314114203232233201
+333130111103041105432335554425563336553354644636442535232426663555233561411155441141043224222010012
+312212201132343322145345553535664245625533624525664643365243662555535264351443134313513234012331221
+011333130444110221131515113246666656324635243225344332434632456366452653566435553532552112112032213
+003210044223303252524443535666334622643542665555535443466362254665353552645422322315242341403403033
+332242132003212314455253226563552223235563544473757777463333354424552234253661232434112101403421313
+312040001231533414324525522532442523565457455447433474553354466333564253445332235523141420440313010
+104312121145333553241636634542265565346747675566465377577443456755332424665356465551313315142001113
+110333013334354152356462424322235575357437745776573354343644766475636435423634252312511111331140311
+141131432332153121364256656254575433447565743764665765654744447464344666636246462421234232204031121
+210421344342113545663322535663655666645644654374543656737477764537567335662535465542244214221230310
+343204325255142551422324234344756654634734465544578576856737376665544467336453352353351443433343304
+133102301254412144555533353653547573665778577574784474658644875673576674676562255566151145351220020
+223224344451344155434562566467465366767464565858754657655754558766475466334253422436442224555331011
+414134415213314456325425437336367533788666656447548675457765658746477537745433342326452115553504140
+210220312315314644352222464334765645485454558884884488448467888485637473436652422342535312532412012
+410423143113532346654334464376736884864787878768676457866557654777446347447647354324563313343220203
+123243144133262345545256434334564557855848445554744857555585647647767444654456422535563521235243101
+001221553423336564562666565736587774456465648898999685976544845644768477675755364556264352421541240
+122455431434364334357455445775865787578877575556698669577858545764465455557447574253635442532141334
+411322422344655432444773444737544688648489665565766575656669686646756668737355663445622544353343501
+100452234113255564277755453355766887888586995558877975687759596677857745857655536652566326321412212
+300321555452652544547664377576778647768898965888758668657676868865468558763557437755625566245113434
+343134514136456336357653376657445885886886867655777985785856897895876848466663747375233322523121142
+114541412565432526734546638486445869798568898996999669867895689986867586854774447772523645343252212
+335525335324365625374537668645856485977698886978879966598557868688888875488534663477325444313251455
+005254243666643553335555487677767596587886656767889998979868697788864858685633474575633523331321214
+312215232353626454653665786656777659797585696766967999978995665688555458666466575656533425421315124
+455254144343565245534457487587747957689887878877887789789877655695559745874753576745665245552435435
+052531252233234335647575675676896959999677999989776697788798799996668944567556466567723324364342355
+054243123465333465754648858585758857559769786667689667798989789966569746575885756753326434235251553
+324142315545624734655445888787888855777696799978997976798969776559679997446665443364532234642425322
+331143113242355447635758688655678979588766798866877787866789899598967898587775667633445363664512251
+142522126265354464773765445857886955789988699988879777868696666776665574854564573735562433654124245
+532514343454323667477744576876799789966977669979989877788977667859777599677745877635536544533143253
+344545426243435744343376464578856699899887978997787989998696799797577777567558475657764653542225144
+253432255553235755377468677456777795699966888787887897879866699998975869654575775746563265454212522
+121223425445367534767578484546968968987668897897978877788669687696598856456654576464556544566231332
+541542252523453663537744676876766989777978898799799789989976678998559565865588533754744432534552324
+342114233543525554546576868665598999696998978979879977987969766966565589668874563547473562232334521
+154335346326353677637687666857966758686688987899878897798796999698597787658557467346733342433315211
+313415365663355547557456858557996769697967868987797887978766688789758887858685456373733366455413432
+112141226362543644556378788749969857997887797989888978987886666675989658844678673543374265335634453
+112344252456244637356468588448876696598986989977798878899877688657895999588557866537366554326242445
+444133113256243335654555768868996955579688996889877998999988677775777665746458546336675245444214445
+234143214235456765755554485688978868779989788989888799789778886996959575685568655457755333642253523
+235444232433252456333444744474656795876689967766878786986699689687798885758464357333464234652444511
+134335515644564474374558768467685896979687996677696868679888676599687655687665676534546554262215313
+443322212224554654475565646767558876567696869686869989977786668597857957566578644636342255264553155
+351215324422333544473344745468768999876569887768769996669869678668866778486668443437545655326415211
+354341132423642657557355868866688587767577676879969777769668697986957456447443473365526525552443133
+133153153354566553334634756678877589665868987689669698978968675766875684856466676656353354241225525
+041433511462563343556756567546857779869988956966767967889656585869798548484854554667465554331321231
+103335423462624233763574365478864686795899959589689896779758775998668657746475666776465443242543435
+415341553545553364343664774665645559686665696597976597558655877598848478474764637573322426514444521
+413135352325454455433647757684556576588586787695669988795756586694645754467574467654265363444411132
+122435422332525436647775654665744648796566885895865887875987998558664677466374446462544654214553452
+143451324343325455537645354344848887559958665997958657685695686664885868463663654564245522354335452
+140345552145363346546744346775884776848557878758757558976668655876767454657544744652355561245512220
+133424122115264566663754443543484774687588567588968968566797884785655454474764444336453641334422411
+430225343531365542622366437654657767744546456986698585956784588658557534576676755525444445134332144
+132141154343324524552434363747334746874878878657686665786765646665775334476375453564326252242351042
+011240412422452444635423754373666875644444877848545768684576568878887556577455663243454333511112202
+124122143452533543243334456547633558557745885486486856674558847678437564344733462422223421121444342
+202111352125551452552345257745435343756687677668545668488787887785774565433534422436534555541524032
+011111153312344355323634663576735753767584575558746877488666764437644637363343242526551231451302400
+203434244145452344656634524547376766563577586448468666748847734375474353362264444436151534124313440
+342314103434454513633362623574747357563655344675786685458353544566755333765363343261543224532134214
+241334002225235424466266566237646456443535447765555375756456463336545335555533523435455432354023021
+304231030435325552536325564235753645736364544545664344543735763537673554536646543341445533213004022
+304322241414212423545425226254344543473444376365575545753674674374655565655245546552152132141034020
+210042001023332321132342634254523347463543745557464437754357577655734546455355541325323345031443030
+300414014030231115124123223265262436374677453653356356346477645632536532655643253535142244120121021
+001312300013141454533135443642526632266555375344736735657644344335566325235451153515513142034100330
+013201431240135541445522126524463364266264655654676555767756454256556363364435532235434021101023233
+111022343031223352312335526234546554625335526364667352235436424655365253354412251324330304334340121
+020301221001412242411521315324665665444335552536345444562424265464323663523253335324112004213243300
+200003330101140324114255532334623565323564544246446342553545244566663322411321421331334123322132332
+111201102322233423425523514545515466424463642252526633545566223643433135415424254141242411023230022
+020231110313114023022353552251344225432366626243523233645624534554615322132224421032322440221031201
+301022321122422204341332335144544431266225323454554263662363634613554225253332343112422302332121301
+003212121330022234213114334313435533321232365626526434454643352531424544444522540021023414301300021
+002120113123011130334332255411142544515153523532265342254412514344521512353310211103000231031031011
+022203312301242240003143035455131453355133544225251133255421242244332211125211002432133432232223122
+012123230121332102102424233251314432151355431432134121155141444345425134423412430343100031011112021
+020112120011000300140413323004541541313533412411343535545541114212354343042322023310233133333311001
+021211311100312300343030212031113424325144412424131143321533111542453240031234420030132023031301100
+201110012103213102203214024221011425542134412551412254115235145223401121144333313120222002303312001

aoc_8/input_test.txt

@@ -0,0 +1,5 @@
+30373
+25512
+65332
+33549
+35390

aoc_8/src/lib.rs

@@ -0,0 +1,163 @@
+use std::cmp::Ordering;
+use std::fmt::{Debug, Formatter};
+
+use take_until::TakeUntilExt;
+
+#[derive(Eq, PartialEq, Hash, Clone)]
+struct Tree {
+    pub x: usize,
+    pub y: usize,
+    pub value: u32,
+}
+
+impl Debug for Tree {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}:{}[{}]", self.x, self.y, self.value)
+    }
+}
+
+impl PartialOrd for Tree {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for Tree {
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.value.cmp(&other.value)
+    }
+}
+
+pub fn part1(input_path: &str) -> Option<u32> {
+    let patch = parse_input(input_path)?;
+    let width = patch[0].len() - 1;
+    let height = patch.len() - 1;
+    let mut visibles = (width + height) * 2;
+
+    for x_tree in 1..patch[0].len() - 1 {
+        for y_tree in 1..patch.len() - 1 {
+            let current_tree = &patch[x_tree][y_tree];
+
+            // Get the line of the current tree
+            let line = &patch[x_tree];
+            // Get the column of the current tree
+            let col = &patch
+                .iter()
+                .map(|value| &value[y_tree])
+                .collect::<Vec<&Tree>>();
+
+            /* Split the line and column on the current tree */
+            let mut split_line = line.split(|other_tree| other_tree == current_tree);
+            let mut split_column = col.split(|other_tree| other_tree == &current_tree);
+
+            /* For each side, we retrieve the optional max height of all the tree */
+            let left = split_line.next()?.iter().max();
+            let right = split_line.next()?.iter().max();
+            let top = split_column.next()?.iter().max();
+            let bottom = split_column.next()?.iter().max();
+
+            // If there is a taller tree of all 4 sides, then the tree is NOT visible, else, well,
+            // it is.
+            match (right, left, top, bottom) {
+                (Some(r), Some(l), Some(t), Some(b))
+                    if r >= current_tree
+                        && l >= current_tree
+                        && t >= &current_tree
+                        && b >= &current_tree => {}
+                _ => {
+                    visibles += 1;
+                }
+            }
+        }
+    }
+    Some(visibles as u32)
+}
+
+pub fn part2(input_path: &str) -> Option<usize> {
+    let patch = parse_input(input_path)?;
+    let mut scenic_scores = 0;
+    for x_tree in 1..patch[0].len() - 1 {
+        for y_tree in 1..patch.len() - 1 {
+            let current_tree = &patch[x_tree][y_tree];
+
+            // Get the line of the current tree
+            let line = &patch[x_tree];
+            // Get the column of the current tree
+            let col = &patch
+                .iter()
+                .map(|value| &value[y_tree])
+                .collect::<Vec<&Tree>>();
+
+            /* Split the line and column on the current tree */
+            let mut split_line = line.split(|other_tree| other_tree == current_tree);
+            let mut split_column = col.split(|other_tree| other_tree == &current_tree);
+
+            // For each side, count the number of tree until we encounter a higher tree
+            let left = split_line
+                .next()?
+                .iter()
+                .rev() // Trees are on the left, we need to read the list from right to left
+                .take_until(|x| current_tree <= x)
+                .count();
+            let right = split_line
+                .next()?
+                .iter()
+                .take_until(|x| current_tree <= x)
+                .count();
+            let top = split_column
+                .next()?
+                .iter()
+                .rev() // Trees are on the top, we need to read the list from bottom to top
+                .take_until(|x| current_tree <= x)
+                .count();
+            let bottom = split_column
+                .next()?
+                .iter()
+                .take_until(|x| current_tree <= x)
+                .count();
+
+            scenic_scores = scenic_scores.max(right * left * top * bottom);
+        }
+    }
+    Some(scenic_scores)
+}
+
+fn parse_input(input_path: &str) -> Option<Vec<Vec<Tree>>> {
+    let mut patch: Vec<Vec<Tree>> = vec![];
+
+    std::fs::read_to_string(input_path)
+        .ok()?
+        .lines()
+        .enumerate()
+        .for_each(|(index_x, line)| {
+            patch.push(
+                line.split_whitespace()
+                    .flat_map(|line| line.chars().enumerate())
+                    .filter_map(|(index_y, value)| {
+                        let value = value.to_digit(10)?;
+                        Some(Tree {
+                            x: index_x,
+                            y: index_y,
+                            value,
+                        })
+                    })
+                    .collect(),
+            );
+        });
+    Some(patch)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{part1, part2};
+
+    #[test]
+    pub fn test_part1() {
+        assert_eq!(part1("input_test.txt"), Some(21))
+    }
+
+    #[test]
+    pub fn test_part2() {
+        assert_eq!(part2("input_test.txt"), Some(8))
+    }
+}

aoc_8/src/main.rs

@@ -0,0 +1,11 @@
+use aoc_8::{part1, part2};
+
+fn main() {
+    if let Some(x) = part1("input.txt") {
+        println!("Result part 1: {x}");
+    }
+
+    if let Some(x) = part2("input.txt") {
+        println!("Result part 2: {x}");
+    }
+}