One, ungolfed

1 files changed, 33 insertions, 0 deletions

diff --git a/2020/21/solve.js b/2020/21/solve.js
new file mode 100644
index 0000000..ac50371
--- /dev/null
+++ b/2020/21/solve.js
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+const { _, performance } = require("perf_hooks");
+const fs = require("fs");
+const data = fs.readFileSync("input", "utf8").split("\n");
+
+function partOne() {
+  const foods = data.map((x) => ({
+    ingredients: x.split(" (contains ")[0].split(" "),
+    allergens: x.split(" (contains ")[1].split(")")[0].split(", "),
+  }));
+
+  const allergens = new Map();
+  for (let food of foods) {
+    for (let allergen of food.allergens) {
+      const prev = allergens.get(allergen);
+      let matching;
+      if (prev)
+        matching = new Set([...food.ingredients].filter((x) => prev.has(x)));
+      else matching = new Set(food.ingredients);
+      allergens.set(allergen, matching);
+    }
+  }
+  const all = foods.map((x) => x.ingredients).flat();
+  const matching = [
+    ...new Set([...allergens.values()].reduce((a, b) => [...a, ...b], [])),
+  ];
+  return all.filter((x) => !matching.includes(x)).length;
+}
+
+const tic = performance.now();
+console.log(partOne());
+//console.log(partTwo());
+const toc = performance.now();
+console.log("TIME: " + ((toc - tic) / 1000).toFixed(6) + " seconds");