Day 4

Day 04/Part 1/index.ts

@@ -0,0 +1,58 @@
+import fs from 'node:fs';
+
+export default function runner(input: string) {
+  fs.readFile(`./${input}`, 'utf8', async (err, data) => {
+    if (err) throw err;
+    let count = 0;
+    let grid: string[][] = []
+
+    data.split("\n").forEach((value, index) => {
+      for (let i = 0; i < value.length; i++) {
+        if (grid[i] === undefined) grid[i] = []
+        if (grid[i] === undefined) throw new Error();
+        // @ts-ignore
+        grid[i][index] = value.charAt(i)
+      }
+    })
+
+    for (let x = 0; x < grid.length; x++) {
+      // @ts-ignore
+      for (let y = 0; y < grid[x].length; y++) {
+        const found = findWord(grid, x, y, "X")
+        count+=found;
+      }
+    }
+
+    console.log(count)
+  })
+}
+
+function findWord(grid: string[][], x: number, y: number, char: string, dx: number = 0, dy: number = 0): number {
+  // @ts-ignore
+  if (x < 0 || x === grid.length || y < 0 || y === grid[x].length) {
+    return 0;
+  }
+  // @ts-ignore
+  if (grid[x][y] === char) {
+    switch (char) {
+      case 'X':
+        let found = 0;
+        for (let dX = -1; dX < 2; dX++) {
+          for (let dY = -1; dY < 2; dY++) {
+            if (dX === 0 && dY === 0) continue;
+            if (findWord(grid, x + dX, y + dY, 'M', dX, dY) != 0) found++;
+          }
+        }
+        return found;
+      case 'M':
+        return findWord(grid, x + dx, y + dy, 'A', dx, dy)
+      case 'A':
+        return findWord(grid, x + dx, y + dy, 'S', dx, dy)
+      case 'S':
+        return 1;
+    }
+  } else {
+    return 0;
+  }
+  return 0;
+}