53 lines
1.2 KiB
TypeScript
53 lines
1.2 KiB
TypeScript
const txt = await Deno.readTextFile("input.txt");
|
|
const map = txt.split("\n").map((row) => row.trim().split(""));
|
|
|
|
function isOutOfBounds(map: string[][], [x, y]: [number, number]) {
|
|
const w = map[0].length;
|
|
const h = map.length;
|
|
return x < 0 || x >= w || y < 0 || y >= h;
|
|
}
|
|
|
|
const patterns = [
|
|
["M", "M", "S", "S"],
|
|
["M", "S", "M", "S"],
|
|
["S", "M", "S", "M"],
|
|
["S", "S", "M", "M"],
|
|
];
|
|
const patternPositions = [
|
|
[-1, -1],
|
|
[1, -1],
|
|
[-1, 1],
|
|
[1, 1],
|
|
];
|
|
|
|
function findXMasPatternInPos(
|
|
map: string[][],
|
|
[x, y]: [number, number],
|
|
) {
|
|
if (isOutOfBounds(map, [x, y])) {
|
|
return 0;
|
|
}
|
|
if (map[y][x] != "A") {
|
|
return 0;
|
|
}
|
|
let count = 0;
|
|
patterns.forEach((pattern) => {
|
|
for (let i = 0; i < pattern.length; i++) {
|
|
const [dx, dy] = patternPositions[i];
|
|
const [nx, ny] = [x + dx, y + dy];
|
|
if (isOutOfBounds(map, [nx, ny]) || map[ny][nx] != pattern[i]) {
|
|
return;
|
|
}
|
|
}
|
|
count++;
|
|
});
|
|
return count;
|
|
}
|
|
|
|
let count = 0;
|
|
for (let i = 0; i < map.length; i++) {
|
|
for (let j = 0; j < map[0].length; j++) {
|
|
count += findXMasPatternInPos(map, [j, i]);
|
|
}
|
|
}
|
|
console.log(count);
|