Merge pull request #41 from hildjj/cleanup

cleanup
hildjj · Dec 20, 2024 · 248e4d7 · 248e4d7
2 parents 414e54d + 3821cb9
commit 248e4d7
Showing 1 changed file with 28 additions and 43 deletions.
diff --git a/day20.ts b/day20.ts
@@ -1,11 +1,14 @@
-import { PointSet } from './lib/rect.ts';
+import { Counter } from './lib/counter.ts';
 import { AllDirs, Point, PointMap, Rect } from './lib/rect.ts';
 import { type MainArgs, parseFile } from './lib/utils.ts';
 import { BinaryHeap } from '@std/data-structures';
 
 type Parsed = string[][];
 
-function astar(r: Rect, start: Point, end: Point): PointSet {
+function astar(r: Rect): Point[] {
+  const [start] = r.filter((v) => v === 'S');
+  const [end] = r.filter((v) => v === 'E');
+
   const gScore = new PointMap([[start, 0]]);
   const fScore = new PointMap([[start, 0]]);
   const prev = new PointMap<Point>();
@@ -19,10 +22,10 @@ function astar(r: Rect, start: Point, end: Point): PointSet {
     const g = gScore.get(p)!;
 
     if (p.equals(end)) {
-      const ps = new PointSet();
+      const ps: Point[] = [];
       let n: Point | undefined = end;
       while (n) {
-        ps.add(n);
+        ps.push(n);
         n = prev.get(n);
       }
       return ps;
@@ -42,68 +45,50 @@ function astar(r: Rect, start: Point, end: Point): PointSet {
     }
   }
 
-  return new PointSet();
+  return [];
 }
 
-function part1(inp: Parsed): number {
-  const r = new Rect(inp);
-  const [start] = r.filter((v) => v === 'S');
-  const [end] = r.filter((v) => v === 'E');
-
-  const ps = astar(r, start, end);
-  const pss = ps.size;
-  const target = pss - 100;
+function part1(ps: Point[]): number {
+  const pslen = ps.length;
   let tot = 0;
-  let pcount = 0;
-  for (const p of ps) {
-    let qcount = 0;
-    for (const q of ps) {
-      if (p.equals(q)) {
-        continue;
-      }
+
+  for (let pcount = 0; pcount < pslen; pcount++) {
+    const p = ps[pcount];
+    for (let qcount = pcount + 2; qcount < pslen; qcount++) {
+      const q = ps[qcount];
       const d = p.manhattan(q);
       if (d === 2) {
-        if ((pcount + (pss - qcount) + 1) <= target) {
+        if ((pcount + d - qcount - 1) <= -100) {
           tot++;
         }
       }
-      qcount++;
     }
-    pcount++;
   }
   return tot;
 }
 
-function part2(inp: Parsed): number {
-  const r = new Rect(inp);
-  const [start] = r.filter((v) => v === 'S');
-  const [end] = r.filter((v) => v === 'E');
-
-  const ps = astar(r, start, end);
-  const pss = ps.size;
-  const target = pss - 100;
+function part2(ps: Point[]): number {
+  const pslen = ps.length;
   let tot = 0;
-  let pcount = 0;
-  for (const p of ps) {
-    let qcount = 0;
-    for (const q of ps) {
-      if (p.equals(q)) {
-        continue;
-      }
+  for (let pcount = 0; pcount < pslen; pcount++) {
+    const p = ps[pcount];
+    for (let qcount = pcount + 2; qcount < pslen; qcount++) {
+      const q = ps[qcount];
       const d = p.manhattan(q);
-      if (d <= 20) {
-        if ((pcount + (pss - qcount) + d - 1) <= target) {
+      if ((d > 1) && (d <= 20)) {
+        if ((pcount + d - qcount - 1) <= -100) {
           tot++;
         }
       }
-      qcount++;
     }
-    pcount++;
   }
   return tot;
 }
 
 export default async function main(args: MainArgs): Promise<[number, number]> {
   const inp = await parseFile<Parsed>(args);
-  return [part1(inp), part2(inp)];
+  const r = new Rect(inp);
+  const ps = astar(r);
+
+  return [part1(ps), part2(ps)];
 }