update with day04 and first puzzle of day05

2025-12-05 01:36:41 -05:00
parent 1b2b0f4edd
commit 93f795cd2c
8 changed files with 1640 additions and 1 deletions
--- a/day04/js/day04a.js
+++ b/day04/js/day04a.js
@@ -0,0 +1,94 @@
+import { promises as fsPromises } from "node:fs";
+
+async function asyncReadFile(filename) {
+    try {
+        const contents = await fsPromises.readFile(filename, "utf-8");
+
+        const arr = contents.split(/\r?\n/);
+
+        return arr;
+    } catch (err) {
+        console.error(err);
+    }
+}
+
+const useTestData = false;
+
+const testDataToParse = `
+..@@.@@@@.
+@@@.@.@.@@
+@@@@@.@.@@
+@.@@@@..@.
+@@.@@@@.@@
+.@@@@@@@.@
+.@.@.@.@@@
+@.@@@.@@@@
+.@@@@@@@@.
+@.@.@@@.@.
+`;
+
+const dataToParse = await asyncReadFile("../input.txt");
+
+const rows = useTestData
+    ? testDataToParse
+          .trim()
+          .split("\n")
+          .map((val) => Array.from(val))
+    : dataToParse.map((val) => Array.from(val));
+const newData = Array.from({ length: rows.length }, () =>
+    new Array(rows[0].length).fill(".")
+);
+
+let countWithLessThanFourAdjacent = 0;
+
+rows.forEach((row, rowIndex) => {
+    row.forEach((val, colIndex) => {
+        if (val !== "@") return;
+
+        let adjacentCount = 0;
+
+        if (rowIndex > 0 && rows[rowIndex - 1][colIndex] === "@")
+            adjacentCount++; // UM
+        if (
+            rowIndex > 0 &&
+            colIndex < row.length - 1 &&
+            rows[rowIndex - 1][colIndex + 1] === "@"
+        )
+            adjacentCount++; // UR
+        if (colIndex < row.length - 1 && row[colIndex + 1] === "@")
+            adjacentCount++; // MR
+        if (
+            rowIndex < rows.length - 1 &&
+            colIndex < row.length - 1 &&
+            rows[rowIndex + 1][colIndex + 1] === "@"
+        )
+            adjacentCount++; // DR
+        if (rowIndex < rows.length - 1 && rows[rowIndex + 1][colIndex] === "@")
+            adjacentCount++; // DM
+        if (
+            rowIndex < rows.length - 1 &&
+            colIndex > 0 &&
+            rows[rowIndex + 1][colIndex - 1] === "@"
+        )
+            adjacentCount++; // DL
+        if (colIndex > 0 && row[colIndex - 1] === "@") adjacentCount++; // LM
+        if (
+            rowIndex > 0 &&
+            colIndex > 0 &&
+            rows[rowIndex - 1][colIndex - 1] === "@"
+        )
+            adjacentCount++; // UL
+
+        if (adjacentCount < 4) {
+            countWithLessThanFourAdjacent++;
+            newData[rowIndex][colIndex] = "x";
+        } else newData[rowIndex][colIndex] = "@";
+    });
+});
+
+console.log(`Found ${countWithLessThanFourAdjacent}`);
+
+if (useTestData)
+    console.log("\n", {
+        newData: `\n${newData.map((row) => row.join("")).join(`\n`)}`,
+    });