Solve day15 deno.ts (#100)

Author: Arxcis

days/day-15/io/arxcis.input

@@ -0,0 +1,6 @@
+15
+5
+1
+4
+7
+0

days/day-15/io/arxcis.output

@@ -0,0 +1,2 @@
+1259
+689

days/day-15/solutions/day15.ts

@@ -0,0 +1,16 @@
+import { whatIsTheNthSpokenNumber } from "../../../lib/whatIsTheNthSpokenNumber.ts"
+const input = (await Deno.readTextFile("/dev/stdin"))
+const lines = [...input.matchAll(/\d+/g)]
+
+const numbers = lines
+  .map(([it]) => parseInt(it))
+
+// Part 1
+{
+  console.log(`${whatIsTheNthSpokenNumber(numbers, 2020)}`)
+}
+
+// Part 2
+{
+  console.log(`${whatIsTheNthSpokenNumber(numbers, 30000000)}`)
+}

days/day-15/test.sh

@@ -7,6 +7,7 @@ echo ""
 echo "--- Day 15: --- Rambunctious Recitation ---"
 #$D/../../lang/go.sh     "$D/solutions/*.go"  "$D/io/*"
 #$D/../../lang/sml.sh    "$D/solutions/*.sml" "$D/io/*"
+$D/../../lang/deno.sh   "$D/solutions/*.ts"  "$D/io/*"
 $D/../../lang/python.sh "$D/solutions/*.py"  "$D/io/*"
-#$D/../../lang/deno.sh   "$D/solutions/*.ts"  "$D/io/*"
 echo ""
+

lib/whatIsTheNthSpokenNumber.test.ts

@@ -0,0 +1,38 @@
+import { whatIsTheNthSpokenNumber } from "./whatIsTheNthSpokenNumber.ts"
+
+expect(`The ${4}th spoken number`, 0, whatIsTheNthSpokenNumber([0,3,6], 4))
+expect(`The ${5}th spoken number`, 3, whatIsTheNthSpokenNumber([0,3,6], 5))
+expect(`The ${6}th spoken number`, 3, whatIsTheNthSpokenNumber([0,3,6], 6))
+expect(`The ${7}th spoken number`, 1, whatIsTheNthSpokenNumber([0,3,6], 7))
+expect(`The ${8}th spoken number`, 0, whatIsTheNthSpokenNumber([0,3,6], 8))
+expect(`The ${9}th spoken number`, 4, whatIsTheNthSpokenNumber([0,3,6], 9))
+expect(`The ${10}th spoken number`, 0, whatIsTheNthSpokenNumber([0,3,6], 10))
+
+expect(`The ${4}th spoken number`, 0, whatIsTheNthSpokenNumber([2,1,3], 4))
+expect(`The ${5}th spoken number`, 0, whatIsTheNthSpokenNumber([2,1,3], 5))
+expect(`The ${6}th spoken number`, 1, whatIsTheNthSpokenNumber([2,1,3], 6))
+
+expect(`The ${2020}th spoken number`, 10, whatIsTheNthSpokenNumber([2,1,3], 2020))
+expect(`The ${2020}th spoken number`, 27, whatIsTheNthSpokenNumber([1,2,3], 2020))
+expect(`The ${2020}th spoken number`, 78, whatIsTheNthSpokenNumber([2,3,1], 2020))
+expect(`The ${2020}th spoken number`, 438, whatIsTheNthSpokenNumber([3,2,1], 2020))
+expect(`The ${2020}th spoken number`, 1836, whatIsTheNthSpokenNumber([3,1,2], 2020))
+expect(`The ${2020}th spoken number`, 1259, whatIsTheNthSpokenNumber([15,5,1,4,7,0], 2020))
+
+expect("The 30000000th spoken number", 175594, whatIsTheNthSpokenNumber([0,3,6], 30000000))
+expect("The 30000000th spoken number", 2578, whatIsTheNthSpokenNumber([1,3,2], 30000000))
+expect("The 30000000th spoken number", 3544142, whatIsTheNthSpokenNumber([2,1,3], 30000000))
+expect("The 30000000th spoken number", 261214, whatIsTheNthSpokenNumber([1,2,3], 30000000))
+expect("The 30000000th spoken number", 6895259, whatIsTheNthSpokenNumber([2,3,1], 30000000))
+expect("The 30000000th spoken number", 18, whatIsTheNthSpokenNumber([3,2,1], 30000000))
+expect("The 30000000th spoken number", 362, whatIsTheNthSpokenNumber([3,1,2], 30000000))
+
+
+
+function expect<T>(name: string, expected: T, actual: T) {
+  if (expected === actual) {
+    console.info(`[TEST PASS ✅] Expected ${name} to be ${expected} Actual: ${actual}`)
+  } else {
+    console.info(`[TEST FAIL ❌] Expected ${name} to be ${expected} Actual: ${actual}`)
+  }
+}

lib/whatIsTheNthSpokenNumber.ts

@@ -0,0 +1,69 @@
+type SpokenNumberType = {
+  value: number;
+  lastSpokenTurn: number;
+  spokenTurnBeforeThat?: number;
+}
+
+export function whatIsTheNthSpokenNumber(initialNumbers: number[], N: number): number{
+
+  //
+  // Inital round where everyone speaks the initial numbers in sequential order
+  //
+  const spokenNumbers = initialNumbers.map((num, i) => ({
+    value: num,
+    lastSpokenTurn: i+1,
+  })) as SpokenNumberType[];
+
+  const spokenMap = new Map(spokenNumbers.map(it => [it.value, it]));
+
+  //
+  // Actual game starts here, where the next number is calculated based on what was previously spoken.
+  //
+
+  // if initial numbers are [1,2,3] -> should be 3th turn now with lastspoken number 3
+  let turn = spokenNumbers.length;
+  let lastSpokenNumber = spokenNumbers[spokenNumbers.length-1]
+
+  while (turn < N) {
+    ++turn;
+
+    // If the last number is a NEW number which has not been spoken before, speak zero!
+    if (!lastSpokenNumber.spokenTurnBeforeThat) {
+      let zeroNumber = spokenMap.get(0)
+      if (!zeroNumber) {
+        zeroNumber = {
+          value: 0,
+          lastSpokenTurn: turn,
+        }
+        spokenMap.set(0, zeroNumber)
+      } else {
+        zeroNumber.spokenTurnBeforeThat = zeroNumber.lastSpokenTurn
+        zeroNumber.lastSpokenTurn = turn
+      }
+      lastSpokenNumber = zeroNumber
+    } else {
+      // ...else the diff is the next spoken number
+      const diff = lastSpokenNumber.lastSpokenTurn - lastSpokenNumber.spokenTurnBeforeThat
+
+      let nextSpokenNumber = spokenMap.get(diff)
+
+      // if the next spoken number been spoken before...
+      if (nextSpokenNumber) {
+        nextSpokenNumber.spokenTurnBeforeThat = nextSpokenNumber.lastSpokenTurn;
+        nextSpokenNumber.lastSpokenTurn = turn;
+        lastSpokenNumber = nextSpokenNumber
+      } else {
+        // ...else add the next spoken number to the map of spoken numbers
+        const nextSpokenNumber = {
+          value: diff,
+          lastSpokenTurn: turn,
+        } as SpokenNumberType
+
+        spokenMap.set(diff, nextSpokenNumber)
+        lastSpokenNumber = nextSpokenNumber
+      }
+    }
+  }
+
+  return lastSpokenNumber.value;
+}