58 lines
1.3 KiB
TypeScript
58 lines
1.3 KiB
TypeScript
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const txt = await Deno.readTextFile("input.txt");
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const map = txt.split("\n").map((row) => row.trim().split(""));
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const dirs = [-1, 0, 1].flatMap((x) => (
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[-1, 0, 1].map((y) => [x, y])
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)).filter(([x, y]) => x != 0 || y != 0);
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function findXMASInPosDir(
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map: string[][],
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[x, y]: [number, number],
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[dx, dy]: [number, number],
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) {
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const w = map[0].length;
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const h = map.length;
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const str = "XMAS";
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for (let i = 0; i < str.length; i++) {
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// out of bounds
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if (x < 0 || x >= w || y < 0 || y >= h) {
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return false;
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}
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if (map[y][x] != str[i]) {
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return false;
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}
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y += dy;
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x += dx;
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}
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return true;
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}
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function findXMASInPos(map: string[][], [x, y]: [number, number]) {
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let count = 0;
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for (const [dx, dy] of dirs) {
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if (
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findXMASInPosDir(map, [x, y], [dx, dy])
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) {
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count++;
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}
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}
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return count;
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}
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function findXMAS(map: string[][]) {
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const w = map[0].length;
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const h = map.length;
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let count = 0;
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for (let i = 0; i < h; i++) {
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for (let j = 0; j < w; j++) {
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if (map[i][j] == "X") {
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count += findXMASInPos(map, [j, i]);
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}
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}
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}
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return count;
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}
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console.log(findXMAS(map));
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