2024D12: Part 1 wip

2024/src/2024/day12/day12.test.ts

@@ -0,0 +1,15 @@
+import {part1, part2} from "./day12";
+
+describe('2024 Day 12', () => {
+    test('Part 1', async () => {
+        expect(await part1('testInput1')).toEqual(772);
+        expect(await part1('testInput2')).toEqual(140);
+        expect(await part1('testInput2')).toEqual(1930);
+        expect(await part1('input')).toEqual(44444);
+    });
+
+    test('Part 2', async () => {
+        expect(await part2('testInput1')).toEqual(31);
+        expect(await part2('input')).toEqual(29379307);
+    });
+});

2024/src/2024/day12/day12.ts

@@ -0,0 +1,38 @@
+import path from "node:path";
+import {readInputLineByLine} from "@utils/io";
+import {Coord, getNeighborCoords, getNeighbors, Grid, readLinesToGrid} from "@utils/grid";
+import * as module from "node:module";
+
+export async function part1(inputFile: string) {
+    return await day12(inputFile, calcAreaAndPerimeter);
+}
+
+export async function part2(inputFile: string) {
+    return await day12(inputFile);
+}
+
+async function day12(inputFile: string, calcFn?: (grid: Grid) => number) {
+    const inputPath = path.join(__dirname, inputFile);
+    const lines = await readInputLineByLine(inputPath);
+
+    return calcFn?.(readLinesToGrid(lines));
+}
+
+function calcAreaAndPerimeter(grid: Grid) {
+    let sum = 0;
+    const perimeterMap: Map<string, number> = new Map();
+    const areaMap: Map<string, number> = new Map();
+
+    for (const [coord, cell] of grid) {
+        const neighbors = getNeighbors(Coord.deserialize(coord), grid);
+        const perimeter = 4 - neighbors.filter(n => n === cell).length;
+        perimeterMap.set(cell, (perimeterMap.get(cell) || 0) + perimeter);
+        areaMap.set(cell, (areaMap.get(cell) || 0) + 1);
+    }
+
+    for (let [key, value] of perimeterMap) {
+        sum += value * areaMap.get(key)!;
+    }
+
+    return sum;
+}

2024/src/2024/day12/testInput1

@@ -0,0 +1,5 @@
+OOOOO
+OXOXO
+OOOOO
+OXOXO
+OOOOO

2024/src/2024/day12/testInput2

@@ -0,0 +1,4 @@
+AAAA
+BBCD
+BBCC
+EEEC

2024/src/2024/day12/testInput3

@@ -0,0 +1,10 @@
+RRRRIICCFF
+RRRRIICCCF
+VVRRRCCFFF
+VVRCCCJFFF
+VVVVCJJCFE
+VVIVCCJJEE
+VVIIICJJEE
+MIIIIIJJEE
+MIIISIJEEE
+MMMISSJEEE