d12 p1 sol

Author: NullDev

2025/Day_12/part_1.js

@@ -1,3 +1,4 @@
+// @ts-nocheck
 import fs from "node:fs";
 import path from "node:path";
 import { performance } from "node:perf_hooks";
@@ -8,16 +9,111 @@ const __dirname = path.dirname(fileURLToPath(import.meta.url));
 // = Copyright (c) NullDev = //
 // ========================= //
 
-const INPUT = String(fs.readFileSync(path.join(__dirname, "input.txt"))).trim().split("\n");
+const INPUT = String(fs.readFileSync(path.join(__dirname, "input.txt"))).trim().split(/\n\s*\n/);
 
 const pStart = performance.now();
 
-//
-// YOUR CODE HERE
-//
-const result = "...";
+const normal = (
+ cells,
+ minX = Math.min(...cells.map(c => c[0])),
+ minY = Math.min(...cells.map(c => c[1])),
+ norm = cells.map(([x, y]) => [x - minX, y - minY]),
+) => ({
+ cells: norm,
+ key: norm.slice()
+ .sort((a, b) => a[0] - b[0] || a[1] - b[1])
+ .map(([x, y]) => `${x},${y}`)
+ .join(";"),
+ w: Math.max(...norm.map(c => c[0])) + 1,
+ h: Math.max(...norm.map(c => c[1])) + 1,
+});
+
+const mOrient = (
+ rawCells, baseBox = normal(rawCells),
+ { cells: base, w: w0, h: h0 } = baseBox,
+) => {
+ const rot = (x, y, w, h, r) => {
+ if (r === 0) return [x, y];
+ if (r === 1) return [h - 1 - y, x];
+ if (r === 2) return [w - 1 - x, h - 1 - y];
+ return [y, w - 1 - x];
+ };
+
+ const orients = [];
+ const seen = new Set();
+ for (let r = 0; r < 4; r++){
+ const wRot = r % 2 === 0 ? w0 : h0;
+ const rt = base.map(([x, y]) => rot(x, y, w0, h0, r));
+
+ for (let f = 0; f < 2; f++){
+ const { cells, key, w, h } = normal(
+ f ? rt.map(([x, y]) => [wRot - 1 - x, y]) : rt,
+ );
+ if (!seen.has(key)) seen.add(key) && orients.push({ cells, w, h });
+ }
+ }
+
+ return { orients, area: base.length };
+};
+
+const shapes = [];
+INPUT.forEach((block, _, __, l = block.trim().split("\n")) => (
+ shapes[Number(l[0].replace(":", ""))] = mOrient(
+ l.slice(1).flatMap(
+ (row, y) => [...row].map((ch, x) => (ch === "#" ? [x, y] : null)).filter(Boolean),
+ ),
+ )
+));
+
+const res = INPUT.pop()?.trim().split("\n").filter(Boolean).filter((
+ line, _, __,
+ [dim, rest] = line.split(":"),
+ [W, H] = dim.match(/(\d+)x(\d+)/).slice(1).map(Number),
+ counts = rest.trim().split(/\s+/).map(Number),
+) => {
+ if (
+ counts.reduce((s, c, i) => s + c * (shapes[i]?.area || 0), 0) > (W * H)
+ ) return false;
+
+ const pl = shapes.map(() => []);
+ for (let i = 0; i < shapes.length; i++){
+ if (!(counts[i] || 0)) continue;
+ const masks = [];
+ shapes[i].orients.forEach(o => {
+ if (o.w > W || o.h > H) return;
+ for (let y0 = 0; y0 <= H - o.h; y0++){
+ for (let x0 = 0; x0 <= W - o.w; x0++){
+ let mask = 0n;
+ for (const [dx, dy] of o.cells) mask |= 1n << BigInt((y0 + dy) * W + (x0 + dx));
+ masks.push(mask);
+ }
+ }
+ });
+
+ if (!masks.length) return false;
+ pl[i] = masks;
+ }
+
+ const pieces = counts.flatMap((c, i) => (c ? Array(c).fill(i) : []))
+ .sort((a, b) => pl[a].length - pl[b].length);
+
+ const dfs = (idx, occ) => {
+ if (idx === pieces.length) return true;
+ const opts = pl[pieces[idx]];
+ for (let k = 0; k < opts.length; k++){
+ const m = opts[k];
+ if (m & occ) continue;
+ if (dfs(idx + 1, occ | m)) return true;
+ }
+ return false;
+ };
+
+ return dfs(0, 0n);
+}).length;
+
+// This sht takes about 15s to run but whatever
 
 const pEnd = performance.now();
 
-console.log("<DESCRIPTION>: " + result);
+console.log("REGIONS THAT FIT PRESENTS: " + res);
 console.log(pEnd - pStart);