Solution to P4 from Santiago L. Valdarrama

getLargest.js

//https://blog.svpino.com/2015/05/07/five-programming-problems-every-software-engineer-should-be-able-to-solve-in-less-than-1-hour?utm_content=bufferf0b7c&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

function getLargestNumber(list) {

  var i, str, strLen;
  var listLen = list.length;
  var largestNumDigits = 0;
  var strList = [];
  var sameLengthList = [];

  for (i = 0; i < listLen; i++) {
    str = list[i].toString();
    strList[i] = str;
    strLen = str.length;
    if (strLen > largestNumDigits) largestNumDigits = strLen;
  }

  for (i = 0; i < listLen; i++) {
    str = strList[i];
    for (var j = str.length; j < largestNumDigits; j++) {
      str = str += '9';
    }
    sameLengthList[i] = {index: i, number: parseInt(str, 10)};
  }

  // TODO use mergesort here :P
  sameLengthList = sameLengthList.sort(function(a, b) {
    return (a.number < b.number);
  });

  var result = '';
  for (i = 0; i < listLen; i++) {
    result += strList[sameLengthList[i].index];
  }

  return result;
}

console.log('largest', getLargestNumber([50, 2, 1, 9]));
console.log('largest', getLargestNumber([420, 42, 423]));