From dad2acc413a5e2f72ec655eb6bd8e136f2187690 Mon Sep 17 00:00:00 2001
From: Seth Etter <sethetter@gmail.com>
Date: Tue, 5 Dec 2023 20:53:39 -0600
Subject: [PATCH] split up seed ranges into promises, it worked!

---
 2023/day05/part2.ts | 36 +++++++++++++++++++++++-------------
 2023/day05/test.ts  |  4 ++--
 2 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/2023/day05/part2.ts b/2023/day05/part2.ts
index 0ed8493..1975b49 100644
--- a/2023/day05/part2.ts
+++ b/2023/day05/part2.ts
@@ -6,7 +6,7 @@ if (import.meta.main) {
       new TextDecoder().decode(bytes),
     )
   ).trim();
-  console.log(answer(input));
+  console.log(await answer(input));
 }
 
 type Range = {
@@ -21,9 +21,9 @@ type MapRanges = {
   ranges: Range[];
 };
 
-export function answer(input: string): number {
+export async function answer(input: string): Promise<number> {
   const [seedLine, _, ...mapLines] = input.split("\n");
-  const seedRanges = seedLine
+  const seedRangeLines = seedLine
     .replace("seeds: ", "")
     .split(" ")
     .map((x) => parseInt(x));
@@ -44,18 +44,28 @@ export function answer(input: string): number {
       return { from, to, ranges };
     });
 
-  let minLocNum = Infinity;
-  for (let i = 0; i < seedRanges.length; i += 2) {
-    const from = seedRanges[i];
-    const to = from + seedRanges[i + 1];
-    for (let j = 0; j < to - from; j++) {
-      const seed = seedRanges[i] + j;
-      const locNum = getLocationNumber(seed, mapRanges);
-      if (locNum < minLocNum) minLocNum = locNum;
-    }
+  const seedRanges: [number, number][] = [];
+  for (let i = 0; i < seedRangeLines.length; i += 2) {
+    const from = seedRangeLines[i];
+    const to = from + seedRangeLines[i + 1];
+    seedRanges.push([from, to]);
   }
+  const rangeMins = await Promise.all(
+    seedRanges.map(
+      ([from, to]) =>
+        new Promise<number>((resolve) => {
+          let minLocNum = Infinity;
+          for (let j = 0; j < to - from; j++) {
+            const seed = from + j;
+            const locNum = getLocationNumber(seed, mapRanges);
+            if (locNum < minLocNum) minLocNum = locNum;
+          }
+          return resolve(minLocNum);
+        }),
+    ),
+  );
 
-  return minLocNum;
+  return Math.min(...rangeMins);
 }
 
 function getLocationNumber(seed: number, mapRanges: MapRanges[]): number {
diff --git a/2023/day05/test.ts b/2023/day05/test.ts
index f2962d3..8b123db 100644
--- a/2023/day05/test.ts
+++ b/2023/day05/test.ts
@@ -42,7 +42,7 @@ Deno.test("part1", () => {
   assertEquals(p1.answer(examples), 35);
 });
 
-Deno.test("part2", () => {
+Deno.test("part2", async () => {
   const examples = [
     "seeds: 79 14 55 13",
     "",
@@ -79,5 +79,5 @@ Deno.test("part2", () => {
     "60 56 37",
     "56 93 4",
   ].join("\n");
-  assertEquals(p2.answer(examples), 46);
+  assertEquals(await p2.answer(examples), 46);
 });
-- 
2.51.2