update with day04 and first puzzle of day05

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`)}`,
+    });

day04/js/day04b.js

@@ -0,0 +1,115 @@
+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 countAdjacentRolls = (rows) => {
+    const newData = structuredClone(rows);
+    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] = "@";
+        });
+    });
+
+    return {
+        count: countWithLessThanFourAdjacent,
+        newRows: newData,
+    };
+};
+
+const useTestData = false;
+
+const testDataToParse = `
+..@@.@@@@.
+@@@.@.@.@@
+@@@@@.@.@@
+@.@@@@..@.
+@@.@@@@.@@
+.@@@@@@@.@
+.@.@.@.@@@
+@.@@@.@@@@
+.@@@@@@@@.
+@.@.@@@.@.
+`;
+
+const dataToParse = await asyncReadFile("../input.txt");
+
+let rollData = useTestData
+    ? testDataToParse
+          .trim()
+          .split("\n")
+          .map((val) => Array.from(val))
+    : dataToParse.map((val) => Array.from(val));
+
+let lastCount = -1;
+let totalCount = 0;
+
+while (lastCount !== 0) {
+    const { count, newRows } = countAdjacentRolls(rollData);
+
+    console.log(`Found ${count}`);
+
+    if (useTestData)
+        console.log("\n", {
+            newRows: newRows.map((row) => row.join("")).join(`\n`),
+        });
+
+    totalCount += count;
+    lastCount = count;
+    rollData = newRows;
+}
+
+console.log(`Final count: ${totalCount}`);