add day 11 solution

11/a.test.ts

@@ -0,0 +1,79 @@
+import { expect, test } from "bun:test";
+
+function zip<T>(arr: T[][]): T[][] {
+    const result: T[][] = [];
+    for (let i = 0; i < arr[0].length; i++) {
+        result.push(arr.map((a) => a[i]));
+    }
+    return result;
+}
+
+function solution(input: string) {
+    const grid = input.split("\n").map((line) => line.split(""));
+
+    const emptyRows = new Set();
+    for (let i = 0; i < grid.length; i++) {
+        const isEmpty = grid[i].every((ch) => ch === ".");
+        if (isEmpty) {
+            emptyRows.add(i);
+        }
+    }
+
+    const emptyCols = new Set();
+    const zipped = zip(grid);
+    for (let i = 0; i < zipped.length; i++) {
+        const isEmpty = zipped[i].every((ch) => ch === ".");
+        if (isEmpty) {
+            emptyCols.add(i);
+        }
+    }
+
+    const galaxies = [];
+    for (let i = 0; i < grid.length; i++) {
+        for (let j = 0; j < grid[0].length; j++) {
+            const ch = grid[i][j];
+            if (ch === "#") {
+                galaxies.push({ row: i, col: j });
+            }
+        }
+    }
+
+    let ans = 0;
+    const scale = 2;
+
+    for (let i = 0; i < galaxies.length; i++) {
+        for (let j = i + 1; j < galaxies.length; j++) {
+            const g1 = galaxies[i];
+            const g2 = galaxies[j];
+
+            for (let k = Math.min(g1.row, g2.row); k < Math.max(g1.row, g2.row); k++) {
+                ans += emptyRows.has(k) ? scale : 1;
+            }
+
+            for (let k = Math.min(g1.col, g2.col); k < Math.max(g1.col, g2.col); k++) {
+                ans += emptyCols.has(k) ? scale : 1;
+            }
+        }
+    }
+
+    return ans;
+}
+
+test("example", async () => {
+    const file = Bun.file(`${import.meta.dir}/example.txt`);
+    const input = await file.text();
+
+    const actual = solution(input);
+    const expected = 374;
+    expect(actual).toBe(expected);
+});
+
+test("puzzle input", async () => {
+    const file = Bun.file(`${import.meta.dir}/input.txt`);
+    const input = await file.text();
+
+    const actual = solution(input);
+    const expected = 9974721;
+
+    expect(actual).toBe(expected);
+});

11/b.test.ts

@@ -0,0 +1,78 @@
+import { expect, test } from "bun:test";
+
+function zip<T>(arr: T[][]): T[][] {
+    const result: T[][] = [];
+    for (let i = 0; i < arr[0].length; i++) {
+        result.push(arr.map((a) => a[i]));
+    }
+    return result;
+}
+
+function solution(input: string, scale = 2) {
+    const grid = input.split("\n").map((line) => line.split(""));
+
+    const emptyRows = new Set();
+    for (let i = 0; i < grid.length; i++) {
+        const isEmpty = grid[i].every((ch) => ch === ".");
+        if (isEmpty) {
+            emptyRows.add(i);
+        }
+    }
+
+    const emptyCols = new Set();
+    const zipped = zip(grid);
+    for (let i = 0; i < zipped.length; i++) {
+        const isEmpty = zipped[i].every((ch) => ch === ".");
+        if (isEmpty) {
+            emptyCols.add(i);
+        }
+    }
+
+    const galaxies = [];
+    for (let i = 0; i < grid.length; i++) {
+        for (let j = 0; j < grid[0].length; j++) {
+            const ch = grid[i][j];
+            if (ch === "#") {
+                galaxies.push({ row: i, col: j });
+            }
+        }
+    }
+
+    let ans = 0;
+
+    for (let i = 0; i < galaxies.length; i++) {
+        for (let j = i + 1; j < galaxies.length; j++) {
+            const g1 = galaxies[i];
+            const g2 = galaxies[j];
+
+            for (let k = Math.min(g1.row, g2.row); k < Math.max(g1.row, g2.row); k++) {
+                ans += emptyRows.has(k) ? scale : 1;
+            }
+
+            for (let k = Math.min(g1.col, g2.col); k < Math.max(g1.col, g2.col); k++) {
+                ans += emptyCols.has(k) ? scale : 1;
+            }
+        }
+    }
+
+    return ans;
+}
+
+test("example", async () => {
+    const file = Bun.file(`${import.meta.dir}/example.txt`);
+    const input = await file.text();
+
+    const actual = solution(input, 100);
+    const expected = 8410;
+    expect(actual).toBe(expected);
+});
+
+test("puzzle input", async () => {
+    const file = Bun.file(`${import.meta.dir}/input.txt`);
+    const input = await file.text();
+
+    const actual = solution(input, 1_000_000);
+    const expected = 702770569197;
+
+    expect(actual).toBe(expected);
+});

11/example.txt

@@ -0,0 +1,10 @@
+...#......
+.......#..
+#.........
+..........
+......#...
+.#........
+.........#
+..........
+.......#..
+#...#.....