Solve day 11

2024/day06/lib.ts

@@ -1,4 +1,4 @@
-import { applyOffset, Coordinate } from '@helper';
+import { applyOffset, Coordinate, valueAtCoord } from '@helper';
 import { ORTHONAL_OFFSETS } from '@constants';
 
 export type Direction = 'up' | 'down' | 'right' | 'left';
@@ -15,8 +15,8 @@ export const nextDirection = (direction: Direction): Direction => {
 
 export const offsetForDirection = (direction: Direction) =>
 	({
-		up: ORTHONAL_OFFSETS.bottom,
-		down: ORTHONAL_OFFSETS.top,
+		up: ORTHONAL_OFFSETS.top,
+		down: ORTHONAL_OFFSETS.bottom,
 		left: ORTHONAL_OFFSETS.left,
 		right: ORTHONAL_OFFSETS.right,
 	})[direction];
@@ -30,7 +30,7 @@ export const walk = (
 		current,
 		offsetForDirection(currentDirection),
 	);
-	const valueAtNextStep = (matrix[potentialStep.row] ?? [])[potentialStep.col];
+	const valueAtNextStep = valueAtCoord(matrix, potentialStep);
 
 	if (!valueAtNextStep) {
 		return [[current, currentDirection]];

2024/day09/part2.ts

@@ -7,15 +7,6 @@ const files = parsedSizes.map((size, index) => {
 	const id = index % 2 ? null : Math.floor(index / 2);
 	return { size, id };
 });
-/* This is a parser for part1
- * eventhough this algorithm is optimized on part 2 it can also solve part 1
- * ...double as fast as the designated part 1 algorithm
- *
-const files = parsedSizes.flatMap((size, index) => {
-	const id = index % 2 ? null : Math.floor(index / 2);
-	return Array.from({ length: size }, () => ({ size: 1, id }));
-});
-*/
 
 type Group = (typeof files)[number];
 

2024/day10/lib.ts

@@ -17,8 +17,7 @@ export const getFinalCoords = (
 			const nextCoord = applyOffset(coord, offset);
 			return [nextCoord, valueAtCoord(matrix, nextCoord)] as const;
 		})
-		.filter(([_, num]) => num === value + 1)
-		.map(([c]) => c);
+		.filter(([_, num]) => num === value + 1);
 
-	return neighbooringCoords.flatMap((c) => getFinalCoords(matrix, c));
+	return neighbooringCoords.flatMap(([c]) => getFinalCoords(matrix, c));
 };

2024/day11/lib.ts

@@ -0,0 +1,15 @@
+export const engraveStone = (stone: number) => {
+	if (stone === 0) {
+		return [1];
+	}
+	const stoneString = `${stone}`;
+	if (stoneString.length % 2 === 0) {
+		const middlePoint = stoneString.length / 2;
+		return [
+			parseInt(stoneString.slice(0, middlePoint)),
+			parseInt(stoneString.slice(middlePoint)),
+		];
+	}
+
+	return [stone * 2024];
+};

2024/day11/part1.ts

@@ -0,0 +1,29 @@
+import { loadData, mapToInt, showVisualization, words } from '@helper';
+import { engraveStone } from './lib';
+
+const input = await loadData();
+const initialStones = mapToInt(words(input));
+
+const cache = new Map<number, number[]>();
+
+const cachedEngraving = (stone: number) => {
+	const cached = cache.get(stone);
+	if (cached) {
+		return cached;
+	}
+
+	const calculated = engraveStone(stone);
+	cache.set(stone, calculated);
+	return calculated;
+};
+
+let stones = initialStones;
+for (let i = 0; i < 25; i++) {
+	stones = stones.flatMap(cachedEngraving);
+}
+
+if (showVisualization()) {
+	console.log(stones.join(' '));
+}
+
+console.log(stones.length);

2024/day11/part2.ts

@@ -0,0 +1,36 @@
+import {
+	countGroups,
+	loadData,
+	mapToInt,
+	mapValues,
+	showVisualization,
+	sum,
+	mergeObjects,
+	words,
+} from '@helper';
+import { engraveStone } from './lib';
+
+const input = await loadData();
+const stones = mapToInt(words(input));
+
+function proccessStoneCount(stoneCounts: Record<string | number, number>) {
+	const counts = Object.entries(stoneCounts).map(([stone, count]) => {
+		const newStones = engraveStone(parseInt(stone));
+		return mapValues(countGroups(newStones), (v) => v! * count);
+	});
+	return mergeObjects(counts, sum);
+}
+
+let counts = countGroups(stones) as Record<number, number>;
+for (let i = 0; i < 75; i++) {
+	counts = proccessStoneCount(counts);
+}
+
+if (showVisualization()) {
+	const stoneGroups = Object.entries(counts).map(([stone, length]) =>
+		Array.from({ length }, () => stone).join(' '),
+	);
+	console.log(stoneGroups.join(' '));
+}
+
+console.log(sum(Object.values(counts)));

helpers/index.ts

@@ -27,6 +27,7 @@ export * from './removeDoubleWhitespaces';
 export * from './transpose';
 export * from './countGroups';
 export * from './lcm';
+export * from './mergeObjects';
 export * from './matrix/getCoordinate';
 export * from './matrix/getNextToCoordinate';
 export * from './matrix/newMatrix';

helpers/mergeObjects.ts

@@ -0,0 +1,26 @@
+import { unique } from './unique';
+
+// TODO: Test and document it
+// TODO: preserve key type (numbers are turned to strings)
+
+export function mergeObjects<T>(
+	objects: Record<string | number, T>[],
+	conflictResolver: (values: T[]) => T,
+) {
+	const keys = unique(objects.flatMap(Object.keys));
+
+	const merged: Record<string, T> = {};
+
+	for (const key of keys) {
+		const initialValues = objects
+			.filter((obj) => key in obj)
+			.map((obj) => obj[key]);
+		const newValue =
+			initialValues.length === 1
+				? initialValues[0]
+				: conflictResolver(initialValues);
+		merged[key] = newValue;
+	}
+
+	return merged;
+}

input/2024/day11.debug

@@ -0,0 +1 @@
+125 17

runNewest

@@ -7,6 +7,7 @@ PART=1
 DATA=debug
 COPY=false
 VIS=false
+MEASURE=false
 
 PROJECT_ROOT="$PWD"
 while [ ! -f "$PROJECT_ROOT/README.md" ]; do
@@ -29,6 +30,7 @@ usage() {
 	echo "  -D --data      Use real input data or just debug (default: debug) (options: debug solve)"
 	echo "  -c --copy      Copy the answer (default: false)"
 	echo "  -v --vis       Show cool little visualizations (default: false)"
+	echo "  -m --measure   Show cool little visualizations (default: false)"
 	exit 1
 }
 
@@ -86,6 +88,10 @@ while [[ $# -gt 0 ]]; do
 			VIS=true
 			shift
 			;;
+		-m|--measure)
+			MEASURE=true
+			shift
+			;;
 		*)
 			usage
 			;;
@@ -132,8 +138,16 @@ export PART=$PART
 export DATA=$DATA
 export VIS=$VIS
 
+start_time=$(date +%s%N)
+
 SOLUTION=$(bun run "$FILE_PATH" "$INPUT_PATH" | tee /dev/tty)
 
+if [ "$MEASURE" == true ]; then
+	end_time=$(date +%s%N)
+	elapsed_time=$(( (end_time - start_time) / 1000000 ))
+	echo "${elapsed_time}ms"
+fi
+
 if [ "$COPY" == true ]; then
 	echo "$SOLUTION" | sed -r 's/\x1B\[[0-9;]*m//g' | wl-copy
 fi