ITS DONE

2021/24.js

@@ -0,0 +1,36 @@
+function day24(input, part2) {
+    let lines = input.split("\n")
+    let ops = lines.splitOnElement("inp w").filter((e) => e.length).transpose()
+
+    let compareVals = ops[4].map((e) => +e.split(" ").last)
+    let stackVals = ops[14].map((e) => +e.split(" ").last)
+
+    let len = compareVals.length
+
+    let stack = []
+    let num = Array(len).fill()
+
+    for (let i = 0; i < len; i++) {
+        if (compareVals[i] > 0) {
+            stack.push([i, stackVals[i]])
+        } else {
+            num[i] = stack.pop()
+            num[i][1] += compareVals[i]
+            num[num[i][0]] = [i, -num[i][1]]
+        }
+    }
+
+    for (let i = 0; i < len; i++) {
+        if (num[i][0] > i) {
+            num[i] = part2 ? Math.max(1, 1 + num[i][1]) : Math.min(9, 9 + num[i][1])
+        } else {
+            num[i] = num[num[i][0]] + num[i][1]
+        }
+    }
+
+    return num.join("")
+}
+
+if (typeof window == "undefined") {
+    module.exports = day24
+}

2021/25.js

@@ -0,0 +1,36 @@
+function step(grid, dir) {
+    let moved = false
+
+    grid.mapMut((e, pt, g) => {
+        let target = dir == 1 ?
+            new Point((pt.x + 1) % g.width, pt.y) :
+            new Point(pt.x, (pt.y + 1) % g.height)
+
+        if (e % 3 == dir && g.get(target) % 3 == 0) {
+            g.set(target, dir * 3)
+            moved = true
+            return e
+        } else {
+            return e * 3 + e
+        }
+    }).mapMut((e) => ((e / 3) | 0) % 3)
+
+    return moved
+}
+
+function day25(input) {
+    let grid = Grid.fromStr(input).mapMut((e) => ".>v".indexOf(e))
+
+    let moved
+    let steps = 0
+
+    do {
+        steps++
+    } while (step(grid, 1) + step(grid, 2))
+
+    return steps
+}
+
+if (typeof window == "undefined") {
+    module.exports = day25
+}

out.js

@@ -1244,7 +1244,7 @@ if (typeof window == "undefined" && process.argv[2] == "test") {
 
 	const year = "2021"
 
-	for (let i = +process.argv[3] || 1; i <= 23; i++) {
+	for (let i = +process.argv[3] || 1; i <= 25; i++) {
 		const func = require(`./${year}/${i}.js`)
 		const input = fs.readFileSync(`./${year}/inputs/${i}`, "utf8")
 		const answers = fs.readFileSync(`./${year}/answers/${i}`, "utf8").split("\n-----\n")

test.js

@@ -3,7 +3,7 @@ if (typeof window == "undefined" && process.argv[2] == "test") {
 
 	const year = "2021"
 
-	for (let i = +process.argv[3] || 1; i <= 23; i++) {
+	for (let i = +process.argv[3] || 1; i <= 25; i++) {
 		const func = require(`./${year}/${i}.js`)
 		const input = fs.readFileSync(`./${year}/inputs/${i}`, "utf8")
 		const answers = fs.readFileSync(`./${year}/answers/${i}`, "utf8").split("\n-----\n")