Cassidoo #325

cassidoo325.js

/**
 * https://buttondown.email/cassidoo/archive/quality-is-not-an-act-it-is-a-habit-will-durant/
 * 
 * Given a list of words and a dictionary of letter scores,
 * find the word with the highest score according to the rules:
 * score = word_length * (sum of letter scores in the word).
 * 
 * If there are multiple words with the same highest score,
 * return the lexicographically smallest one.
 * 
 * Example:
 * 
 * const letterScores = [...Array(26).keys()].reduce(
 *   (scores, i) => ((scores[String.fromCharCode(97 + i)] = i + 1), scores),
 *   {}
 * );
 * // This produces { 'a': 1, 'b': 2, 'c': 3, 'd': 4, ... }
 *
 * const wordList = ["apple", "banana", "cherry", "date", "fig"];
 * scoreWordGame(wordList, letterScores); // 'cherry'
 */ 

// This produces { 'a': 1, 'b': 2, 'c': 3, 'd': 4, ... }
const letterScores = [...Array(26).keys()].reduce(
  (scores, i) => ((scores[String.fromCharCode(97 + i)] = i + 1), scores),
  {}
);

// not supported in all browsers:
// https://caniuse.com/mdn-javascript_builtins_intl_listformat_format
const formatList = new Intl.ListFormat('en', {
  style: 'long',
  type: 'conjunction'
});

// in a tie, the winners have the shortest word length
const breakTieScore = words => {
  const sortedByLength = words.sort((a, b) => a.length - b.length);
  const shortestWordLength = sortedByLength[0].length;
  const winners = sortedByLength.filter(word => word.length === shortestWordLength);

  return `${formatList.format(winners)} win${winners.length > 1 ? '' : 's'}! 🎉`;
}

const scoreWordGame = (wordList, letterScores) => {
  let highScores = [{
    score: 0,
    word: '',
  }];

  wordList.forEach(word => {
    const splitWord = word.split('');

    const score = splitWord.reduce((acc, currChar) => {
      return acc + letterScores[currChar];
    }, 0);

    // console.log(`${word}'s score is ${score}`);

    if (score > highScores[0].score) {
      // keep track of high scores
      highScores = [{
        score,
        word
      }];
    } else if (score === highScores[0].score) {
      // keep track of high score ties
      highScores = [
        ...highScores,
        {
          score, word
        }
      ];
    }
  });

  if (highScores.length === 1) {
    return `${highScores[0].word} wins! 🎉`;
  }

  // more than one winning word
  const tieWords = highScores.map(item => item.word);
  return breakTieScore(tieWords);
};

const wordList1 = ['apple', 'banana', 'cherry', 'date', 'fig'];
console.log(scoreWordGame(wordList1, letterScores)); // cherry

// 'jiffy' and 'miso' have the same score
// but 'miso' wins because it is shorter
const wordList2 = [
  'jiffy',
  'miso',
];
console.log(scoreWordGame(wordList2, letterScores)); // miso

// all the words have the same score of 6
// and there is a 3 way tie
const wordList3 = [
  'abc',
  'aaaaaa',
  'cba',
  'bbb',
];
console.log(scoreWordGame(wordList3, letterScores)); // abc, cba, bbb

// all the words have the same score of 6
// but only 1 winner because 'cc' is the shortest word
const wordList4 = [
  'abc',
  'aaaaaa',
  'cc',
  'bbb',
];
console.log(scoreWordGame(wordList4, letterScores)); // cc