sortRoman Hackerrank

sortRoman.js

// Complete the sortRoman function below.
function sortRoman(names) {
  const namesObj = names.reduce((sum, curr) => {
    const currentSum = sum;
    const [name, order] = curr.split(' ');
    if (!currentSum[name]) {
      currentSum[name] = [];
    }
    currentSum[name].push(curr);
    currentSum[name] = sortByRomanNumerals(currentSum[name]);
    return currentSum;
  }, {});

  const sortedNames = Object.keys(namesObj);
  sortedNames.sort((a, b) => {
    if (a < b) {
      return -1;
    }
    if (a > b) {
      return 1;
    }
    return 0;
  });
  return sortedNames
    .map((o) => namesObj[o])
    .reduce((sum, ar) => {
      return sum.concat(ar);
    }, []);
}

function sortByRomanNumerals(array) {
  const romanNumeralsOrderForReplace = [
    'xl',
    'l',
    'xxx',
    'xx',
    'ix',
    'x',
    'iv',
    'v',
    'iii',
    'ii',
    'i',
  ];
  const romanNumeralsMap = {
    i: 1,
    ii: 2,
    iii: 3,
    iv: 4,
    v: 5,
    ix: 9,
    x: 10,
    xx: 20,
    xxx: 30,
    xl: 40,
    l: 50,
  };
  const arr = array
    .map((a) => {
      const [name, number] = a.split(' ');
      const obj = {
        fullName: a,
        name,
        romanNumber: number,
      };
      let tempNumber = number.toLowerCase();
      romanNumeralsOrderForReplace.forEach((num) => {
        tempNumber = tempNumber.replace(num, `${romanNumeralsMap[num]},`);
      });
      const tempNumberArray = tempNumber.split(',');
      const newNumber = tempNumberArray.reduce((s, c) => {
        return s + (parseInt(c) ? parseInt(c) : 0);
      }, 0);
      obj.number = newNumber;
      return obj;
    })
    .sort((a, b) => a.number - b.number);

  return arr.map((obj) => obj.fullName);
}

sortRoman(['Louis IX', 'Louis VIII']);
sortRoman(['Philippe I', 'Philip II']);