[TASK] Solved Day 10

functions/src/day10.ts

@@ -0,0 +1,87 @@
+import Day from "./day";
+import Utils from "./utils";
+
+const MISSING_CHARACTER_SCORES: {[key: string]: number} = {
+  ")": 1,
+  "]": 2,
+  "}": 3,
+  ">": 4,
+}
+
+class Day10 implements Day {
+
+  part1(input: string[]): number | string {
+
+    return Utils.sum(
+      input.map(s => this.checkSyntax(s))
+        .map(r => r.error === "corrupt" ? this.getCorruptCharacterScore(r.got) : 0)
+    );
+
+  }
+
+  part2(input: string[]): number | string {
+
+    const incompletenessScores = input
+      .map(s => this.checkSyntax(s))
+      .filter(r => r.error === "incomplete")
+      .map(r => r.error === "incomplete" ? this.calculateIncompletenessScore(r.missing) : 0);
+
+    incompletenessScores.sort((a, b) => a - b);
+    return incompletenessScores[Math.floor(incompletenessScores.length / 2)];
+  }
+
+  calculateIncompletenessScore(missing: string): number {
+
+    let score = 0;
+    for (const missingElement of missing) {
+      score *= 5;
+      score += MISSING_CHARACTER_SCORES[missingElement];
+    }
+    return score;
+  }
+
+  getCorruptCharacterScore(char: string): number {
+    switch (char) {
+      case ")": return 3;
+      case "]": return 57;
+      case "}": return 1197;
+      case ">": return 25137;
+      default: throw Error(`Can't find points for character '${char}'`);
+    }
+  }
+
+  checkSyntax(line: string): { error: "corrupt", expected: string, got: string } | { error: "incomplete", missing: string } | { error: "none" } {
+
+    const stack = [];
+    for (const char of line) {
+
+      switch (char) {
+        case "(": stack.push(")"); break;
+        case "[": stack.push("]"); break;
+        case "{": stack.push("}"); break;
+        case "<": stack.push(">"); break;
+        default: {
+          const expected = stack[stack.length - 1];
+          if (expected === char) {
+            stack.pop();
+          } else {
+            return {error: "corrupt", expected, got: char};
+          }
+        }
+      }
+    }
+    if (stack.length === 0) {
+      return { error: "none" }
+    } else {
+      let missing = "";
+      while(stack.length > 0) {
+        missing += stack.pop();
+      }
+      return { error: "incomplete", missing }
+    }
+
+  }
+
+}
+
+export default Day10;

functions/src/index.ts

@@ -11,6 +11,7 @@ import Day6 from "./day6";
 import Day7 from "./day7";
 import Day8 from "./day8";
 import Day9 from "./day9";
+import Day10 from "./day10";
 
 
 // // Start writing Firebase Functions
@@ -36,6 +37,7 @@ export const day = {
   7: functions.region("europe-west1").https.onRequest((request, response) => { processDay(new Day7(), request, response) }),
   8: functions.region("europe-west1").https.onRequest((request, response) => { processDay(new Day8(), request, response) }),
   9: functions.region("europe-west1").https.onRequest((request, response) => { processDay(new Day9(), request, response) }),
+  10: functions.region("europe-west1").https.onRequest((request, response) => { processDay(new Day10(), request, response) }),
 
 }