feat: Day 11 2021 ⭐ 🌟 TypeScript solution

2021/deno/day-11.ts

@@ -0,0 +1,120 @@
+const input = await Deno.readTextFile("./input/day-11.in");
+// const input = await Deno.readTextFile("./input/example.in");
+
+function calcAdj(x: number, y: number, width: number, height: number) {
+  const vector = [0, 1, -1];
+
+  return vector
+    .map((dx) => vector.map((dy) => [dx, dy]))
+    .flat(1)
+    .filter(([dx, dy]) => Math.abs(dx) + Math.abs(dy) > 0)
+    .map(([dx, dy]) => ({ x: x + dx, y: y + dy }))
+    .filter(
+      (coord) =>
+        coord.x >= 0 && coord.x < width && coord.y >= 0 && coord.y < height
+    );
+}
+
+const createOctopus = (value: number, x: number, y: number) => {
+  let _value = value;
+
+  return {
+    get value() {
+      return _value;
+    },
+    get hash() {
+      return `${x}:${y}`;
+    },
+    reset() {
+      _value = 0;
+    },
+    radiate() {
+      _value += 1;
+    },
+    x,
+    y
+  };
+};
+
+type Octopus = ReturnType<typeof createOctopus>;
+
+const grid = input
+  .split("\n")
+  .map((row, y) =>
+    row.split("").map((value, x) => createOctopus(Number(value), x, y))
+  );
+
+const width = grid[0].length;
+const height = grid.length;
+
+/**
+ * Part One
+ */
+
+let total_flashes_at_100 = 0;
+
+let step = 0;
+
+while (1) {
+  if (grid.every((row) => row.every((cell) => cell.value === 0))) {
+    break;
+  }
+  step += 1;
+
+  let scheduled: Octopus[] = [];
+
+  for (const row of grid) {
+    for (const oct of row) {
+      oct.radiate();
+
+      if (oct.value > 9) {
+        scheduled.push(oct);
+      }
+    }
+  }
+
+  const flashed = new Set<Octopus>();
+
+  while (1) {
+    const next = scheduled.shift();
+
+    if (next === undefined) {
+      break;
+    }
+
+    if (flashed.has(next)) {
+      continue;
+    }
+
+    flashed.add(next);
+
+    const adj = calcAdj(next.x, next.y, width, height);
+
+    for (const { x, y } of adj) {
+      // radiate neighbors
+      const oct = grid[y][x];
+      oct.radiate();
+
+      if (oct.value > 9) {
+        if (!flashed.has(oct)) {
+          scheduled.push(oct);
+        }
+      }
+    }
+  }
+
+  for (const oct of [...flashed]) {
+    oct.reset();
+
+    if (step <= 100) {
+      total_flashes_at_100 += 1;
+    }
+  }
+}
+
+console.log("Part One:", total_flashes_at_100);
+
+/**
+ * Part Two
+ */
+console.log("Part Two:", step);