Solve 2024-15

2024/15/2024-15.run.xml

@@ -0,0 +1,7 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="2024-15" type="BunRunConfiguration">
+    <option name="program" value="2024/15/run.ts" />
+    <option name="workingDirectory" value="$PROJECT_DIR$" />
+    <method v="2" />
+  </configuration>
+</component>

2024/15/index.test.ts

@@ -0,0 +1,55 @@
+import { describe, expect, it } from 'bun:test';
+import { solveFirst, solveSecond } from './index.ts';
+
+describe('2024-15', () => {
+  const testInput = `##########
+#..O..O.O#
+#......O.#
+#.OO..O.O#
+#..O@..O.#
+#O#..O...#
+#O..O..O.#
+#.OO.O.OO#
+#....O...#
+##########
+
+<vv>^<v^>v>^vv^v>v<>v^v<v<^vv<<<^><<><>>v<vvv<>^v^>^<<<><<v<<<v^vv^v>^
+vvv<<^>^v^^><<>>><>^<<><^vv^^<>vvv<>><^^v>^>vv<>v<<<<v<^v>^<^^>>>^<v<v
+><>vv>v^v^<>><>>>><^^>vv>v<^^^>>v^v^<^^>v^^>v^<^v>v<>>v^v^<v>v^^<^^vv<
+<<v<^>>^^^^>>>v^<>vvv^><v<<<>^^^vv^<vvv>^>v<^^^^v<>^>vvvv><>>v^<<^^^^^
+^><^><>>><>^^<<^^v>>><^<v>^<vv>>v>>>^v><>^v><<<<v>>v<v<v>vvv>^<><<>^><
+^>><>^v<><^vvv<^^<><v<<<<<><^v<<<><<<^^<v<^^^><^>>^<v^><<<^>>^v<v^v<v^
+>^>>^v>vv>^<<^v<>><<><<v<<v><>v<^vv<<<>^^v^>^^>>><<^v>>v^v><^^>>^<>vv^
+<><^^>^^^<><vvvvv^v<v<<>^v<v>v<<^><<><<><<<^^<<<^<<>><<><^^^>^^<>^>v<>
+^^>vv<^v^v<vv>^<><v<^v>^^^>>>^^vvv^>vvv<>>>^<^>>>>>^<<^v>^vvv<>^<><<v>
+v^^>>><<^^<>>^v^<v^vv<>v^<<>^<^v^v><^<<<><<^<v><v<>vv>>v><v^<vv<>v^<<^`;
+  it('first', () => {
+    expect(
+      solveFirst(`########
+#..O.O.#
+##@.O..#
+#...O..#
+#.#.O..#
+#...O..#
+#......#
+########
+
+<^^>>>vv<v>>v<<`)
+    ).toBe(2028);
+    expect(solveFirst(testInput)).toBe(10092);
+  });
+  it('second', () => {
+    expect(
+      solveSecond(`#######
+#...#.#
+#.....#
+#..OO@#
+#..O..#
+#.....#
+#######
+
+<vv<<^^<<^^`)
+    ).toBe(105 + 306 + 207);
+    expect(solveSecond(testInput)).toBe(9021);
+  });
+});

2024/15/index.ts

@@ -0,0 +1,351 @@
+import { replaceChar, sumArray } from '../../utils/array.ts';
+import {
+  type Coordinates,
+  findCoordsOfDigit,
+  getAdjacent,
+  isCoordinateEqual
+} from '../../utils/coordinates.ts';
+
+// TODO: cleanup??
+export function solveFirst(input: string): number {
+  const [rawMap, rawInstructions] = input.split('\n\n');
+  const map = rawMap.split('\n');
+  const instructions = rawInstructions.split('\n').join('');
+
+  // console.log(map);
+  // console.log(instructions);
+
+  const width = map[0].length;
+  const height = map.length;
+
+  let [[x, y]] = findCoordsOfDigit(map, '@');
+
+  replaceChar(map, x, y, '.');
+
+  outer: for (const instruction of instructions) {
+    // console.log(instruction, x, y);
+    const { left, right, down, top } = getAdjacent(map, x, y);
+
+    if (instruction === '>') {
+      if (right === '#') {
+        continue;
+      }
+      if (right === '.') {
+        x++;
+        continue;
+      }
+      if (right === 'O') {
+        let firstFree = 2;
+        while (firstFree + x < width) {
+          if (map[y][firstFree + x] === '#') {
+            continue outer;
+          }
+          if (map[y][firstFree + x] === '.') {
+            break;
+          }
+          firstFree++;
+        }
+        if (firstFree + x >= width) {
+          continue;
+        }
+        replaceChar(map, x + 1, y, '.');
+        replaceChar(map, x + firstFree, y, 'O');
+
+        x++;
+        continue;
+      }
+    } else if (instruction === 'v') {
+      if (down === '#') {
+        continue;
+      }
+      if (down === '.') {
+        y++;
+        continue;
+      }
+
+      if (down === 'O') {
+        let firstFree = 2;
+        while (firstFree + y < height) {
+          if (map[firstFree + y][x] === '#') {
+            continue outer;
+          }
+          if (map[firstFree + y][x] === '.') {
+            break;
+          }
+          firstFree++;
+        }
+        if (firstFree + y >= height) {
+          continue;
+        }
+        replaceChar(map, x, y + 1, '.');
+        replaceChar(map, x, y + firstFree, 'O');
+
+        y++;
+        continue;
+      }
+    } else if (instruction === '<') {
+      if (left === '#') {
+        continue;
+      }
+      if (left === '.') {
+        x--;
+        continue;
+      }
+      if (left === 'O') {
+        let firstFree = -2;
+        while (firstFree + x > 0) {
+          if (map[y][firstFree + x] === '#') {
+            continue outer;
+          }
+          if (map[y][firstFree + x] === '.') {
+            break;
+          }
+          firstFree--;
+        }
+        if (firstFree + x <= 0) {
+          continue;
+        }
+        replaceChar(map, x - 1, y, '.');
+        replaceChar(map, x + firstFree, y, 'O');
+
+        x--;
+        continue;
+      }
+    } else if (instruction === '^') {
+      if (top === '#') {
+        continue;
+      }
+      if (top === '.') {
+        y--;
+        continue;
+      }
+
+      if (top === 'O') {
+        let firstFree = -2;
+        while (firstFree + y > 0) {
+          if (map[firstFree + y][x] === '#') {
+            continue outer;
+          }
+          if (map[firstFree + y][x] === '.') {
+            break;
+          }
+          firstFree--;
+        }
+        if (firstFree + y <= 0) {
+          continue;
+        }
+        replaceChar(map, x, y - 1, '.');
+        replaceChar(map, x, y + firstFree, 'O');
+
+        y--;
+        continue;
+      }
+    }
+    console.log('ERROR!');
+    break;
+  }
+
+  // console.log(map.join('\n'));
+
+  const boxes = findCoordsOfDigit(map, 'O');
+
+  return sumArray(boxes.map(([x, y]) => 100 * y + x));
+}
+
+export function solveSecond(input: string): number {
+  const [rawMap, rawInstructions] = input.split('\n\n');
+  const map = rawMap.split('\n').map((row) =>
+    row
+      .split('')
+      .map((d) => (d === 'O' ? '[]' : d === '@' ? '@.' : d + d))
+      .join('')
+  );
+  const instructions = rawInstructions.split('\n').join('');
+
+  // console.log(map);
+  // console.log(instructions);
+
+  const width = map[0].length;
+
+  let [[x, y]] = findCoordsOfDigit(map, '@');
+
+  replaceChar(map, x, y, '.');
+
+  outer: for (const instruction of instructions) {
+    if (map.some((r) => r.includes('[[') || r.includes(']]'))) {
+      console.log('ERROR!');
+      replaceChar(map, x, y, '@');
+      break;
+    }
+
+    // console.log(map.join('\n'));
+    // console.log(instruction, x, y);
+    const { left, right, down, top } = getAdjacent(map, x, y);
+
+    if (instruction === '>') {
+      if (right === '#') {
+        continue;
+      }
+      if (right === '.') {
+        x++;
+        continue;
+      }
+
+      if (right === '[') {
+        let firstFree = 3;
+        while (firstFree + x < width) {
+          if (map[y][firstFree + x] === '#') {
+            continue outer;
+          }
+          if (map[y][firstFree + x] === '.') {
+            break;
+          }
+          firstFree++;
+        }
+        if (firstFree + x >= width) {
+          continue;
+        }
+        const boxes = map[y].substring(x + 1, x + firstFree);
+        replaceChar(map, x + 2, y, boxes);
+        replaceChar(map, x + 1, y, '.');
+
+        x++;
+        continue;
+      }
+    } else if (instruction === 'v') {
+      if (down === '#') {
+        continue;
+      }
+      if (down === '.') {
+        y++;
+        continue;
+      }
+      const toMove: Coordinates = [];
+      const toMoveDigit: string[] = [];
+      if (down === ']') {
+        toMove.push([x, y + 1], [x - 1, y + 1]);
+        toMoveDigit.push(']', '[');
+      } else if (down === '[') {
+        toMove.push([x, y + 1], [x + 1, y + 1]);
+        toMoveDigit.push('[', ']');
+      }
+      for (let i = 0; i < toMove.length; i++) {
+        const [mX, mY] = toMove[i];
+        const { down: mDown } = getAdjacent(map, mX, mY);
+        if (!mDown) {
+          continue;
+        }
+        if (mDown === '[') {
+          toMove.push([mX, mY + 1], [mX + 1, mY + 1]);
+          toMoveDigit.push('[', ']');
+        } else if (mDown === ']') {
+          toMove.push([mX - 1, mY + 1], [mX, mY + 1]);
+          toMoveDigit.push('[', ']');
+        }
+      }
+      // TODO: filter unique??
+      // console.log(toMove);
+
+      if (toMove.some(([mX, mY]) => map[mY + 1][mX] === '#')) {
+        continue;
+      }
+      // console.log('move', 1);
+      toMove.forEach(([mX, mY], i) =>
+        replaceChar(map, mX, mY + 1, toMoveDigit[i])
+      );
+      toMove.forEach(
+        ([mX, mY]) =>
+          !toMove.some((c) => isCoordinateEqual(c, [mX, mY - 1])) &&
+          replaceChar(map, mX, mY, '.')
+      );
+      y++;
+      continue;
+    } else if (instruction === '<') {
+      if (left === '#') {
+        continue;
+      }
+      if (left === '.') {
+        x--;
+        continue;
+      }
+      if (left === ']') {
+        let firstFree = -3;
+        while (firstFree + x > 0) {
+          if (map[y][firstFree + x] === '#') {
+            continue outer;
+          }
+          if (map[y][firstFree + x] === '.') {
+            break;
+          }
+          firstFree--;
+        }
+        if (firstFree + x <= 0) {
+          continue;
+        }
+        const boxes = map[y].substring(x + firstFree + 1, x);
+        replaceChar(map, x + firstFree, y, boxes);
+        replaceChar(map, x - 1, y, '.');
+
+        x--;
+        continue;
+      }
+    } else if (instruction === '^') {
+      if (top === '#') {
+        continue;
+      }
+      if (top === '.') {
+        y--;
+        continue;
+      }
+      const toMove: Coordinates = [];
+      const toMoveDigit: string[] = [];
+      if (top === ']') {
+        toMove.push([x, y - 1], [x - 1, y - 1]);
+        toMoveDigit.push(']', '[');
+      } else if (top === '[') {
+        toMove.push([x, y - 1], [x + 1, y - 1]);
+        toMoveDigit.push('[', ']');
+      }
+
+      for (let i = 0; i < toMove.length; i++) {
+        const [mX, mY] = toMove[i];
+        const { top: mTop } = getAdjacent(map, mX, mY);
+        if (!mTop) {
+          continue;
+        }
+        if (mTop === '[') {
+          toMove.push([mX, mY - 1], [mX + 1, mY - 1]);
+          toMoveDigit.push('[', ']');
+        } else if (mTop === ']') {
+          toMove.push([mX - 1, mY - 1], [mX, mY - 1]);
+          toMoveDigit.push('[', ']');
+        }
+      }
+      // TODO: filter unique??
+      // console.log(toMove);
+
+      if (toMove.some(([mX, mY]) => map[mY - 1][mX] === '#')) {
+        continue;
+      }
+      // console.log('move', 1);
+      toMove.forEach(([mX, mY], i) =>
+        replaceChar(map, mX, mY - 1, toMoveDigit[i])
+      );
+      toMove.forEach(
+        ([mX, mY]) =>
+          !toMove.some((c) => isCoordinateEqual(c, [mX, mY + 1])) &&
+          replaceChar(map, mX, mY, '.')
+      );
+      y--;
+      continue;
+    }
+    console.log('ERROR!');
+    break;
+  }
+
+  // console.log(map.join('\n'));
+
+  const boxes = findCoordsOfDigit(map, /\[/g);
+
+  return sumArray(boxes.map(([x, y]) => 100 * y + x));
+}

2024/15/run.ts

@@ -0,0 +1,12 @@
+import { join } from 'path';
+import { solveFirst, solveSecond } from './index.ts';
+
+const input = await Bun.file(join(__dirname, 'input.txt')).text();
+
+const firstAnswer = solveFirst(input);
+
+console.log(firstAnswer);
+
+const secondAnswer = solveSecond(input);
+
+console.log(secondAnswer);

utils/array.ts

@@ -135,5 +135,5 @@ export function unique<E>(
  * @param char Char
  */
 export function replaceChar(arr: string[], x: number, y: number, char: string) {
-  arr[y] = arr[y].substring(0, x) + char + arr[y].substring(x + 1);
+  arr[y] = arr[y].substring(0, x) + char + arr[y].substring(x + char.length);
 }