const HIGH_CARD = 1; const PAIR = 2; const TWO_PAIR = 3; const THREE_OF_A_KIND = 4; const STRAIGHT = 5; const FLUSH = 6; const FULL_HOUSE = 7; const POKER = 8; const STRAIGHT_FLUSH = 9; export const bestHands = (hands) => { let maxRank = 0; let maxValue = {}; let result = []; for (const hand of hands) { const handValue = evaluateHand(hand); if (handValue.rank > maxRank) { maxRank = handValue.rank; maxValue = handValue; result = [hand]; } else if (handValue.rank === maxRank) { const handValueComparison = compareHandValues( maxRank, maxValue, handValue, ); if (handValueComparison === 2) { maxValue = handValue; result = [hand]; } else if (handValueComparison === 0) { result.push(hand); } } } return result; }; const evaluateHand = (hand) => { const cards = hand.split(' ').map((card) => { const [value, suit] = card.replace('10', 'T').split(''); return { value, suit }; }); const cardSuits = cards.map((card) => card.suit); const cardValues = cards .map((card) => { switch (card.value) { case 'A': return 14; case 'K': return 13; case 'Q': return 12; case 'J': return 11; case 'T': return 10; default: return Number(card.value); } }) .sort((a, b) => a - b); const isFlush = new Set(cardSuits).size === 1; const isLowestStraight = cardValues.join(',') === '2,3,4,5,14'; if (isLowestStraight) { // Ace has a value of 1 in the lowest straight cardValues.pop(); cardValues.unshift(1); } const isStraight = Math.abs(cardValues[0] - cardValues[cardValues.length - 1]) === 4 && new Set(cardValues).size === 5; const cardValuesCount = Array(15).fill(0); for (const value of cardValues) { cardValuesCount[value]++; } const handValue = { rank: -1 }; if (isStraight && isFlush) handValue.rank = STRAIGHT_FLUSH; else if (cardValuesCount.includes(4)) handValue.rank = POKER; else if (cardValuesCount.includes(3) && cardValuesCount.includes(2)) handValue.rank = FULL_HOUSE; else if (isFlush) handValue.rank = FLUSH; else if (isStraight) handValue.rank = STRAIGHT; else if (cardValuesCount.includes(3)) handValue.rank = THREE_OF_A_KIND; else if (cardValuesCount.filter((value) => value === 2).length === 2) handValue.rank = TWO_PAIR; else if (cardValuesCount.includes(2)) handValue.rank = PAIR; else handValue.rank = HIGH_CARD; switch (handValue.rank) { case STRAIGHT_FLUSH: case STRAIGHT: handValue.highestCard = Math.max(...cardValues); break; case POKER: case FULL_HOUSE: case THREE_OF_A_KIND: case TWO_PAIR: case PAIR: cardValuesCount.forEach((value, index) => { if (value === 4) handValue.quad = index; else if (value === 3) handValue.triplet = index; else if (value === 2) { if (handValue.pair === undefined) handValue.pair = index; else handValue.pair2 = index; } else if (value === 1) { if (handValue.kicker === undefined) handValue.kicker = index; else if (handValue.kicker2 === undefined) handValue.kicker2 = index; else handValue.kicker3 = index; } }); break; case FLUSH: case HIGH_CARD: cardValuesCount.forEach((value, index) => { if (value === 1) { if (handValue.card5 === undefined) handValue.card5 = index; else if (handValue.card4 === undefined) handValue.card4 = index; else if (handValue.card3 === undefined) handValue.card3 = index; else if (handValue.card2 === undefined) handValue.card2 = index; else handValue.card1 = index; } }); break; } return handValue; }; const compareHandValues = (rank, handValue1, handValue2) => { switch (rank) { case STRAIGHT_FLUSH: case STRAIGHT: if (handValue1.highestCard > handValue2.highestCard) return 1; if (handValue1.highestCard < handValue2.highestCard) return 2; return 0; case FLUSH: case HIGH_CARD: if (handValue1.card1 < handValue2.card1) return 2; if (handValue1.card2 > handValue2.card2) return 1; if (handValue1.card2 < handValue2.card2) return 2; if (handValue1.card3 > handValue2.card3) return 1; if (handValue1.card3 < handValue2.card3) return 2; if (handValue1.card4 > handValue2.card4) return 1; if (handValue1.card4 < handValue2.card4) return 2; if (handValue1.card5 > handValue2.card5) return 1; if (handValue1.card5 < handValue2.card5) return 2; return 0; case POKER: if (handValue1.quad > handValue2.quad) return 1; if (handValue1.quad < handValue2.quad) return 2; if (handValue1.kicker > handValue2.kicker) return 1; if (handValue1.kicker < handValue2.kicker) return 2; return 0; case FULL_HOUSE: if (handValue1.triplet > handValue2.triplet) return 1; if (handValue1.triplet < handValue2.triplet) return 2; if (handValue1.pair > handValue2.pair) return 1; if (handValue1.pair < handValue2.pair) return 2; if (handValue1.kicker > handValue2.kicker) return 1; if (handValue1.kicker < handValue2.kicker) return 2; return 0; case THREE_OF_A_KIND: if (handValue1.triplet > handValue2.triplet) return 1; if (handValue1.triplet < handValue2.triplet) return 2; if (handValue1.kicker2 > handValue2.kicker2) return 1; if (handValue1.kicker2 < handValue2.kicker2) return 2; if (handValue1.kicker > handValue2.kicker) return 1; if (handValue1.kicker < handValue2.kicker) return 2; return 0; case TWO_PAIR: if (handValue1.pair2 > handValue2.pair2) return 1; if (handValue1.pair2 < handValue2.pair2) return 2; if (handValue1.pair > handValue2.pair) return 1; if (handValue1.pair < handValue2.pair) return 2; if (handValue1.kicker > handValue2.kicker) return 1; if (handValue1.kicker < handValue2.kicker) return 2; return 0; case PAIR: if (handValue1.pair > handValue2.pair) return 1; if (handValue1.pair < handValue2.pair) return 2; if (handValue1.kicker3 > handValue2.kicker3) return 1; if (handValue1.kicker3 < handValue2.kicker3) return 2; if (handValue1.kicker2 > handValue2.kicker2) return 1; if (handValue1.kicker2 < handValue2.kicker2) return 2; if (handValue1.kicker > handValue2.kicker) return 1; if (handValue1.kicker < handValue2.kicker) return 2; return 0; } return -1; };