Day 18 Part 1 WIP

2024/18/index.ts

@@ -0,0 +1,148 @@
+const fs = require('fs');
+
+const input = fs.readFileSync(__dirname + '/input.txt', 'utf8').split("\n");
+
+interface Coord {
+    x: number,
+    y: number,
+};
+
+enum Dir {
+    Up,
+    Right,
+    Down,
+    Left,
+};
+
+const map: Array<Array<string>> = [];
+
+const width = 71;
+const height = 71;
+
+for (let y = 0; y < height; y++) {
+    if (!map[y]) {
+        map[y] = [];
+    }
+    for (let x = 0; x < width; x++) {
+        map[y][x] = '.';
+    }
+}
+
+for (let i = 0; i < 1024; i++) {
+    const [x, y] = input[i].split(',').map((st: string) => parseInt(st));
+    map[y][x] = '#'
+}
+
+function get(pos: Coord): string {
+    if (map[pos.y] && map[pos.y][pos.x]) {
+        return map[pos.y][pos.x];
+    }
+    return '#';
+}
+
+function set(pos: Coord, val: string): void {
+    map[pos.y][pos.x] = val;
+}
+
+function nextDir(dir: Dir): Dir {
+    const directions = [Dir.Up, Dir.Right, Dir.Down, Dir.Left];
+    const i = (directions.indexOf(dir) + 1) % directions.length;
+    return directions[i];
+}
+function prevDir(dir: Dir): Dir {
+    const directions = [Dir.Up, Dir.Right, Dir.Down, Dir.Left];
+    const i = directions.indexOf(dir) - 1;
+    if (i < 0) {
+        return directions[directions.length - 1];
+    }
+    return directions[i];
+}
+
+function printMap() {
+    const mapClone = map.slice().map((row: Array<string>) => row.slice());
+    console.log(mapClone.map((row: Array<string>) => row.join('')).join("\n"));
+}
+
+function nextCoord(pos: Coord, direction: Dir): Coord {
+    return direction === Dir.Up ? { x: pos.x, y: pos.y - 1 }
+        : (direction === Dir.Right ? { x: pos.x + 1, y: pos.y }
+            : (direction === Dir.Down ? { x: pos.x, y: pos.y + 1 } : { x: pos.x - 1, y: pos.y })
+        );
+}
+
+function isDeadEnd(pos: Coord): boolean {
+    if ((pos.x === 0 && pos.y === 0) || (pos.x === width - 1 && pos.y === width - 1)) {
+        return false;
+    }
+    const adjs = [Dir.Up, Dir.Right, Dir.Down, Dir.Left].map((dir) => get(nextCoord(pos, dir))).join('');
+    return adjs === '###.'
+        || adjs === '##.#'
+        || adjs === '#.##'
+        || adjs === '.###';
+}
+
+function fillDeadEnd(pos: Coord): void {
+    set(pos, '#')
+    for (let dir of [Dir.Up, Dir.Right, Dir.Down, Dir.Left]) {
+        const next = nextCoord(pos, dir);
+        if (get(next) === '.') {
+            if (isDeadEnd(next)) {
+                fillDeadEnd(next);
+            }
+        }
+    };
+}
+printMap();
+console.log("\n");
+
+for (let y = 0; y < height; y++) {
+    for (let x = 0; x < width; x++) {
+        const pos = { x, y };
+        const char = get(pos);
+        if (char !== '.') {
+            continue;
+        }
+        if (isDeadEnd(pos)) {
+            fillDeadEnd(pos);
+        }
+    }
+}
+
+printMap();
+
+//let fastest: number|null = null;
+//
+//const scoreCache: { [key: string]: [number, Coord, Dir] } = {};
+//
+//const branchCache: { [key: string]: number } = {};
+//
+//const scores: Array<number> = [];
+//
+//function getScoresAfterPosition(pos: Coord, dir: Dir, path: Array<string> = []): void {
+//    if (fastest !== null && path.length >= fastest) {
+//        return;
+//    }
+//    [dir, nextDir(dir), prevDir(dir)].forEach((newDir, i) => {
+//        const next = nextCoord(pos, newDir);
+//        const nextStr = `${next.x},${next.y}`;
+//        if (!path.includes(nextStr)) {
+//            if (next.x === width - 1 && next.y === height - 1) {
+//                if (fastest === null || path.length < fastest) {
+//                    fastest = path.length;
+//                }
+//                scores.push(path.length);
+//                return;
+//            } else if (next.x >= 0 && next. x < width && next.y >= 0 && next.y < height && get(next) === '.') {
+//                getScoresAfterPosition(next, newDir, [...path, nextStr]);
+//            }
+//        }
+//    });
+//
+//    return;
+//}
+//
+//getScoresAfterPosition({ x: 0, y: 0 }, Dir.Up, ['0,0']);
+//
+//console.log(scores);
+//const fastestScore = Math.min(...scores);
+//