2023.07

challenges/2023/07.js

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+// Part 1
+const solvePuzzle1 = (input) => getWinnings(input);
+
+// Part 2
+const solvePuzzle2 = (input) => getWinnings(input, true);
+
+// Constants & helpers
+const cardValues = {
+  A: 13,
+  K: 12,
+  Q: 11,
+  J: 10,
+  T: 9,
+  9: 8,
+  8: 7,
+  7: 6,
+  6: 5,
+  5: 4,
+  4: 3,
+  3: 2,
+  2: 1,
+};
+
+const handValues = {
+  five: 7,
+  four: 6,
+  full: 5,
+  three: 4,
+  two: 3,
+  one: 2,
+  high: 1,
+};
+
+const getWinnings = (input, swapJoker = false) => {
+  const hands = input
+    .split('\n')
+    .map((line) => {
+      const [hand, bet] = line.split(' ');
+      return [getHandValues(hand, swapJoker), bet];
+    })
+    .sort(sortHands);
+
+  return hands.reduce((acc, [_, bet], idx) => acc + Number(bet) * (idx + 1), 0);
+};
+
+const sortHands = (handA, handB) => {
+  const [[handValueA, secondaryValuesA], betA, jCountA] = handA;
+  const [[handValueB, secondaryValuesB], betB, jCountB] = handB;
+
+  const copyOfSecondaryValuesA = secondaryValuesA.slice();
+  const copyOfSecondaryValuesB = secondaryValuesB.slice();
+
+  const diff = handValueA - handValueB;
+
+  if (diff === 0) {
+    if ((jCountA || jCountB) && jCountA !== jCountB) {
+      return jCountA - jCountB;
+    }
+
+    while (getLastValue(copyOfSecondaryValuesA) === getLastValue(copyOfSecondaryValuesB)) {
+      copyOfSecondaryValuesA.pop();
+      copyOfSecondaryValuesB.pop();
+    }
+
+    return getLastValue(copyOfSecondaryValuesA) - getLastValue(copyOfSecondaryValuesB);
+  }
+  return diff;
+};
+
+const getHandValues = (hand, swapJoker) => {
+  const cards = {};
+
+  hand.split('').forEach((card) => {
+    cards[card] = cards[card] ? [cards[card][0] + 1, card] : [1, card];
+  });
+
+  let values = Object.values(cards).sort((a, b) => {
+    if (swapJoker && (a[1] === 'J' || b[1] === 'J')) {
+      return a[1] === 'J' ? +1 : -1;
+    }
+    return b[0] - a[0];
+  });
+
+  const secondaryValues = hand
+    .split('')
+    .map((c) => (swapJoker && c === 'J' ? 0 : cardValues[c]))
+    .reverse();
+
+  let jCount;
+
+  if (swapJoker) {
+    jCount = hand.split('J').length - 1;
+
+    if (values[0][0] + jCount >= 5) {
+      values[0][0] = 5;
+    } else if (values[0][0] + jCount >= 2) {
+      values[0][0] = Math.min(values[0][0] + jCount, 4);
+    }
+
+    if (!(values.length === 1 && values[0][1] === 'J')) {
+      values = values.filter((val) => val[1] !== 'J');
+    }
+  }
+
+  return [getHandTypeValue(values), secondaryValues, jCount];
+};
+
+const getHandTypeValue = (values) => {
+  if (values[0][0] === 5) return handValues.five;
+  if (values[0][0] === 4) return handValues.four;
+  if (values[0][0] === 3 && values[1][0] === 2) return handValues.full;
+  if (values[0][0] === 3) return handValues.three;
+  if (values[0][0] === 2 && values[1][0] === 2) return handValues.two;
+  if (values[0][0] === 2) return handValues.one;
+  return handValues.high;
+};
+
+const getLastValue = (array) => array[array.length - 1];
+
+require(__dirname + '/../../utils/test.js').test(__filename, __dirname, solvePuzzle1, '1');
+require(__dirname + '/../../utils/test.js').test(__filename, __dirname, solvePuzzle2, '2');