2021-06

2021/06/part1.mjs

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+import fs from "fs-extra";
+import fp from "lodash/fp.js";
+import _ from "lodash";
+
+export const processInput = (input) =>
+    input.split(',').map( x => parseInt(x) );
+
+export function solution(input,days = 80) {
+    let fish = Array.from({length:8}, ()=>0);
+    input.forEach( x => fish[x]++ );
+
+    for( let i = 0; i< days; i++ ) {
+        const breeders = fish.shift();
+        if(breeders ) {
+            fish[8] = breeders;
+            fish[6] = (fish[6] || 0)  + breeders;
+        }
+   //     console.log(fish);
+    }
+
+    return _.sum(fish);
+};

2021/06/test.mjs

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+import tap from "tap";
+import fs from "fs-extra";
+
+import * as p1 from "./part1.mjs";
+
+const sample = p1.processInput("3,4,3,1,2");
+const input = fs.readFile("input", "utf8").then(p1.processInput);
+
+tap.test("part1", async (t) => {
+    t.equal(p1.solution(await sample, 18), 26);
+    t.equal(p1.solution(await sample), 5934);
+    t.equal(p1.solution(await input), 358214);
+});
+
+tap.test("part2", async (t) => {
+    t.equal(p1.solution(await sample, 256), 26984457539);
+    t.equal(p1.solution(await input, 256), 1622533344325);
+});