Add solution day 10

day_10/example.txt

@@ -0,0 +1,8 @@
+89010123
+78121874
+87430965
+96549874
+45678903
+32019012
+01329801
+10456732

day_10/input.txt

@@ -0,0 +1,54 @@
+543067650323210321032110356789890110710189878760134567
+612148941212306782345091235410765227893258759651021298
+701238932301456798106787549323454336794567549842330807
+898547215450589867287654678892961245987654456732498910
+987656306769678956398013234781870301256003301201567821
+234543215878760145478920105690210982340112210341056932
+109650124981232230569834124567345673451234985452347845
+018744323890341021656765033438454589298545676701037796
+199803210787650110765017842129823672107655677812378987
+785012345654789541874326956010510563201234389983405676
+174321498723498632903455467173421454102348210234514430
+065430239014323721212762398982567876218959650149623521
+145540128765017890101871081071018967327968743898734678
+236692134984178768718981012567894458456876212798604329
+987783005673269659654108923458763349663212108789015012
+896654012562154546743267830309854218767103419276126787
+765780123473043432890154321212903109878756578125435698
+434099874984012301740125654567812893469017647030165556
+323101065765101787434436763058906732154178736543256765
+013298187890678696325569892143215440043289128954343894
+010367296541549045016678765014300351234567037760012983
+329458305032132134787867410967891267653438546891898012
+458789414145010120196986323898763298344129655432743210
+567076523236678743285898456777654101201098766653658901
+456167654107549658374567689985403100312434985567877014
+343228943298938569843210576876312238920125676656986323
+651014543498127478755765435410278947437876985543235434
+743223672567078369876890324320127656506987234350145632
+894102981089569232125981210451256543215432122341076541
+765091234676352101034674323401237894101341001456789830
+014780365445443032126501012532345743103210112565898321
+123689876034321145098432107645236743254101101876543210
+094545763125210056788943258896107858969010332987674301
+785430432106782169877652349787567967678321245696784561
+876021569045893458965601654343478914565414326781093870
+987109878010432167014298710234323901258905015492012901
+789219894324569052123109620123217892109876012323458692
+654308765543678743013234538994106543010870965410069783
+789877787632189852101110145885287676521961871012178654
+034565896601087601211001406776896789437652676523468743
+121053795542194512389132312345445676548943989430549012
+262342187634765433498545434531230107401232104321678298
+876533014123892324567696526540043298340981010780890187
+983414523016101019876587017832134781256672125690743296
+032101654327892100345678789901295690764543434321652345
+123089789236743981234589654800387789835678987787601336
+854176590187656876104310343211456876544549016098543223
+965765410194545675465231230898565963233432145123210112
+876894321243232980370110141767653210112321039654101101
+146765232100101061289879852632154100203410128789210322
+036787103761267876518768763543069911012543454376325412
+123498654854356987405650654985678892327632567215436701
+210567569983543292314321569876301765438761078904589898
+325456478754330101223433478765432654349652987615678765

day_10/solve_1.ts

@@ -0,0 +1,76 @@
+export type HeightMap = number[][];
+
+export async function readMap(path: string): Promise<HeightMap> {
+    const text = await Deno.readTextFile(path);
+    return text.split("\n").map((row) =>
+        row.trim().split("").map((cell) => {
+            const ret = parseInt(cell);
+            if (isNaN(ret)) {
+                return -5;
+            }
+            return ret;
+        })
+    );
+}
+
+export function displayMap(map: HeightMap) {
+    console.log(map.map((row) => row.map(x=> x < 0 ? "." : x).join("")).join("\n"));
+}
+
+export type Pos = [number, number];
+
+export function getCell(map: HeightMap, [x, y]: Pos): number {
+    return map[y][x];
+}
+
+export const TOP_HEIGHT = 9;
+
+export function countReachableTop(pos: Pos, map: HeightMap): number {
+    const stack: {
+        pos: Pos;
+        height: number;
+    }[] = [];
+    const visited = new Set<string>();
+    stack.push({ pos, height: getCell(map, pos) });
+    let count = 0;
+    while (stack.length > 0) {
+        const { pos, height } = stack.pop()!;
+        const [x, y] = pos;
+        if (getCell(map, pos) === TOP_HEIGHT) {
+            if (visited.has(pos.toString())) {
+                continue;
+            }
+            visited.add(pos.toString());
+            count++;
+            continue;
+        }
+        for (const [dx, dy] of [[1, 0], [-1, 0], [0, 1], [0, -1]]) {
+            const [nx, ny] = [x + dx, y + dy];
+            if (nx < 0 || nx >= map[0].length || ny < 0 || ny >= map.length) {
+                continue;
+            }
+            const nheight = getCell(map, [nx, ny]);
+            if (nheight == height + 1) {
+                stack.push({ pos: [nx, ny], height: nheight });
+            }
+        }
+    }
+    return count;
+}
+
+if (import.meta.main) {
+    const map = await readMap("input.txt");
+    displayMap(map);
+    const data = map.map((row, y) => {
+        return row.map((cell, x) => {
+            if (cell === 0) {
+                const count = countReachableTop([x, y], map);
+                console.log("count reachable top from", [x, y]);
+                return count;
+            }
+            return -5;
+        });
+    });
+    displayMap(data);
+    console.log(data.flat().reduce((a, b) => a + (b < 0 ? 0 : b ), 0));
+}

day_10/solve_2.ts

@@ -0,0 +1,51 @@
+import { Pos, HeightMap, getCell, TOP_HEIGHT, readMap, displayMap } from "./solve_1.ts";
+
+function countReachableTop(pos: Pos, map: HeightMap): number {
+    const stack: {
+        pos: Pos;
+        height: number;
+    }[] = [];
+    // const visited = new Set<string>();
+    stack.push({ pos, height: getCell(map, pos) });
+    let count = 0;
+    while (stack.length > 0) {
+        const { pos, height } = stack.pop()!;
+        const [x, y] = pos;
+        if (getCell(map, pos) === TOP_HEIGHT) {
+            // if (visited.has(pos.toString())) {
+            //     continue;
+            // }
+            // visited.add(pos.toString());
+            count++;
+            continue;
+        }
+        for (const [dx, dy] of [[1, 0], [-1, 0], [0, 1], [0, -1]]) {
+            const [nx, ny] = [x + dx, y + dy];
+            if (nx < 0 || nx >= map[0].length || ny < 0 || ny >= map.length) {
+                continue;
+            }
+            const nheight = getCell(map, [nx, ny]);
+            if (nheight == height + 1) {
+                stack.push({ pos: [nx, ny], height: nheight });
+            }
+        }
+    }
+    return count;
+}
+
+if (import.meta.main) {
+    const map = await readMap("input.txt");
+    displayMap(map);
+    const data = map.map((row, y) => {
+        return row.map((cell, x) => {
+            if (cell === 0) {
+                const count = countReachableTop([x, y], map);
+                console.log("count reachable top from", [x, y]);
+                return count;
+            }
+            return -5;
+        });
+    });
+    displayMap(data);
+    console.log(data.flat().reduce((a, b) => a + (b < 0 ? 0 : b ), 0));
+}