[TASK] Solved Day 14

functions/src/day14.ts

@@ -0,0 +1,151 @@
+import Day from "./day";
+import Utils from "./utils";
+
+type CharCounts = {[key: string]: bigint};
+
+class Day14 implements Day {
+
+  part1(input: string[]): number | string {
+
+    const { orig, mapping } = Day14.parseInput(input);
+
+    let current = orig;
+    for (let step = 0; step < 10; step++) {
+      current = this.executeStep(current, mapping);
+    }
+
+    const counts: {[key: string]: number} = {};
+    for (const c of current) {
+      if (c in counts) {
+        counts[c]++;
+      } else {
+        counts[c] = 1;
+      }
+    }
+
+
+    return Math.max(...Object.values(counts)) - Math.min(...Object.values(counts));
+  }
+
+  private static parseInput(input: string[]): { orig: string, mapping: Map<string, Map<string, string>>} {
+    const orig = input[0];
+
+    const mapping = new Map<string, Map<string, string>>();
+    for (const line of input.slice(2)) {
+
+      const splitIndex = line.indexOf("->");
+      const from = line.substr(0, splitIndex).trim();
+      const firstChar = from[0];
+      const secondChar = from[1];
+      const to = line.substr(splitIndex + 2).trim();
+
+      const existingMapping = mapping.get(firstChar);
+      if (existingMapping) {
+        existingMapping.set(secondChar, to);
+      } else {
+        mapping.set(firstChar, new Map<string, string>([[secondChar, to]]));
+      }
+    }
+
+    return { orig, mapping };
+  }
+
+  private executeStep(orig: string, mapping: Map<string, Map<string, string>>): string {
+
+    let res = "";
+    for (let i = 0; i < orig.length - 1; i++) {
+
+      const char = orig[i];
+      res += char;
+      const firstCharMatch = mapping.get(char);
+      if (firstCharMatch) {
+        const secondChar = orig[i + 1];
+        const toAdd = firstCharMatch.get(secondChar);
+        if (toAdd) {
+          res += toAdd;
+        }
+      }
+    }
+    // Add the last character as it's not included in the result
+    res += orig[orig.length - 1];
+
+    return res;
+  }
+
+  part2(input: string[]): number | string {
+
+    const { orig, mapping } = Day14.parseInput(input);
+
+    let counts: CharCounts = {};
+    const cache = new Map<string, CharCounts>();
+    for (let i = 0; i < orig.length - 1; i++) {
+
+      const firstChar = orig[i];
+      const secondChar = orig[i + 1];
+
+      this.addOne(firstChar, counts);
+      this.mergeIntoLeft(counts, this.calculateRecursive(firstChar, secondChar, mapping, 40, cache));
+
+    }
+    this.addOne(orig[orig.length - 1], counts);
+
+    return (Utils.bigMax(Object.values(counts)) - Utils.bigMin(Object.values(counts))).toString();
+  }
+
+  /**
+   * Returns the amount of added element of each type
+   */
+  calculateRecursive(firstChar: string, secondChar: string, mappings: Map<string, Map<string, string>>, stepsLeft: number, cache: Map<string, CharCounts>): CharCounts {
+
+    if (stepsLeft === 0) return {};
+
+    const cacheKey = firstChar + secondChar + stepsLeft;
+    const cachedResult = cache.get(cacheKey);
+    if (cachedResult) return cachedResult;
+
+    const res = {};
+
+    const firstCharMatch = mappings.get(firstChar);
+    if (firstCharMatch) {
+      const toAdd = firstCharMatch.get(secondChar);
+      if (toAdd) {
+        this.addOne(toAdd, res);
+        this.mergeIntoLeft(res, this.calculateRecursive(firstChar, toAdd, mappings, stepsLeft - 1, cache));
+        this.mergeIntoLeft(res, this.calculateRecursive(toAdd, secondChar, mappings, stepsLeft - 1, cache));
+      }
+    }
+
+    cache.set(cacheKey, res);
+    return res;
+
+  }
+
+  mergeIntoLeft(left: CharCounts, right: CharCounts) {
+
+    for (const rightKey in right) {
+      if (rightKey in left) {
+        left[rightKey] += right[rightKey];
+      } else {
+        left[rightKey] = right[rightKey];
+      }
+    }
+  }
+
+  addOne(char: string, counts: CharCounts) {
+
+    if (char in counts) {
+      counts[char]++;
+    } else {
+      counts[char] = 1n;
+    }
+  }
+
+  // calculateCounts(pair: string, mappings: Map<string, Map<string, string>>, cache: Map<string, Map<number, {[key: string]: bigint}>>): {[key: string]: bigint} {
+  //
+  //
+  //
+  // }
+
+}
+
+export default Day14;

functions/src/index.ts

@@ -15,6 +15,7 @@ import Day10 from "./day10";
 import Day11 from "./day11";
 import Day12 from "./day12";
 import Day13 from "./day13";
+import Day14 from "./day14";
 
 
 // // Start writing Firebase Functions
@@ -44,6 +45,7 @@ export const day = {
   11: functions.region("europe-west1").https.onRequest((request, response) => { processDay(new Day11(), request, response) }),
   12: functions.region("europe-west1").https.onRequest((request, response) => { processDay(new Day12(), request, response) }),
   13: functions.region("europe-west1").https.onRequest((request, response) => { processDay(new Day13(), request, response) }),
+  14: functions.region("europe-west1").https.onRequest((request, response) => { processDay(new Day14(), request, response) }),
 
 }
 

functions/src/utils.ts

@@ -21,6 +21,14 @@ class Utils {
     return values.reduce((a, b) => a + b);
   }
 
+  static bigMax(values: bigint[]): bigint {
+    return values.reduce((a, b) => a > b ? a : b);
+  }
+
+  static bigMin(values: bigint[]): bigint {
+    return values.reduce((a, b) => a < b ? a : b);
+  }
+
   static zeroes(length: number): number[] {
 
     const res = [];

input/day/14-example.http

@@ -0,0 +1,23 @@
+POST http://localhost:5001/advent-of-code-2021-911a8/europe-west1/day-14
+Content-Type: text/plain
+
+NNCB
+
+CH -> B
+HH -> N
+CB -> H
+NH -> C
+HB -> C
+HC -> B
+HN -> C
+NN -> C
+BH -> H
+NC -> B
+NB -> B
+BN -> B
+BB -> N
+BC -> B
+CC -> N
+CN -> C
+
+###

input/day/14.http

@@ -0,0 +1,107 @@
+POST http://localhost:5001/advent-of-code-2021-911a8/europe-west1/day-14
+Content-Type: text/plain
+
+CNBPHFBOPCSPKOFNHVKV
+
+CS -> S
+FB -> F
+VK -> V
+HO -> F
+SO -> K
+FK -> B
+VS -> C
+PS -> H
+HH -> P
+KH -> V
+PV -> V
+CB -> N
+BB -> N
+HB -> B
+HV -> O
+NC -> H
+NF -> B
+HP -> B
+HK -> S
+SF -> O
+ON -> K
+VN -> V
+SB -> H
+SK -> H
+VH -> N
+KN -> C
+CC -> N
+BF -> H
+SN -> N
+KP -> B
+FO -> N
+KO -> V
+BP -> O
+OK -> F
+HC -> B
+NH -> O
+SP -> O
+OO -> S
+VC -> O
+PC -> F
+VB -> O
+FF -> S
+BS -> F
+KS -> F
+OV -> P
+NB -> O
+CF -> F
+SS -> V
+KV -> K
+FP -> F
+KC -> C
+PF -> C
+OS -> C
+PN -> B
+OP -> C
+FN -> F
+OF -> C
+NP -> C
+CK -> N
+BN -> K
+BO -> K
+OH -> S
+BH -> O
+SH -> N
+CH -> K
+PO -> V
+CN -> N
+BV -> F
+FV -> B
+VP -> V
+FS -> O
+NV -> P
+PH -> C
+HN -> P
+VV -> C
+NK -> K
+CO -> N
+NS -> P
+VO -> P
+CP -> V
+OC -> S
+PK -> V
+NN -> F
+SC -> P
+BK -> F
+BC -> P
+FH -> B
+OB -> O
+FC -> N
+PB -> N
+VF -> N
+PP -> S
+HS -> O
+HF -> N
+KK -> C
+KB -> N
+SV -> N
+KF -> K
+CV -> N
+NO -> P
+
+###