2022 - Day 2

2022/02/solution.ts

@@ -0,0 +1,79 @@
+const sample = await Deno.readTextFile("sample.txt");
+const input = await Deno.readTextFile("input.txt");
+
+type Object = "rock" | "paper" | "scissor";
+type Outcome = "LOST" | "DRAW" | "WIN";
+
+const scores: Record<Outcome, number> = {
+  LOST: 0,
+  DRAW: 3,
+  WIN: 6,
+} as const;
+
+const objectValues: Record<Object, number> = {
+  rock: 1,
+  paper: 2,
+  scissor: 3,
+} as const;
+
+const objectsWinFrom: Record<Object, Object> = {
+  rock: "scissor",
+  paper: "rock",
+  scissor: "paper",
+} as const;
+
+const codesToObjects: Record<string, Object> = {
+  A: "rock",
+  B: "paper",
+  C: "scissor",
+  X: "rock",
+  Y: "paper",
+  Z: "scissor",
+} as const;
+
+const codesToOutcome: Record<string, Outcome> = {
+  X: "LOST",
+  Y: "DRAW",
+  Z: "WIN",
+} as const;
+
+const solvePart1 = (data: string): number | undefined =>
+  data
+    .split("\n")
+    .filter(Boolean)
+    .map((line) => line.split(" ").map((code) => codesToObjects[code]))
+    .map(([object1, object2]) => {
+      if (object2 === object1) {
+        return scores.DRAW + objectValues[object2];
+      }
+      if (objectsWinFrom[object2] === object1) {
+        return scores.WIN + objectValues[object2];
+      }
+      return scores.LOST + objectValues[object2];
+    })
+    .reduce((sum, value) => sum + value, 0);
+
+console.log("Sample:", solvePart1(sample));
+console.log("Input", solvePart1(input));
+
+const solvePart2 = (data: string): number | undefined =>
+  data
+    .split("\n")
+    .filter(Boolean)
+    .map((line): [Object, Outcome] => {
+      const [objectCode, outcomeCode] = line.split(" ");
+      return [codesToObjects[objectCode], codesToOutcome[outcomeCode]];
+    })
+    .map(([object1, outcome]) => {
+      if (outcome === "DRAW") {
+        return scores.DRAW + objectValues[object1];
+      }
+      if (outcome === "LOST") {
+        return scores.LOST + objectValues[objectsWinFrom[object1]];
+      }
+      return scores.WIN + objectValues[objectsWinFrom[objectsWinFrom[object1]]];
+    })
+    .reduce((sum, value) => sum + value, 0);
+
+console.log("Sample:", solvePart2(sample));
+console.log("Input", solvePart2(input));