Discussion on: Daily Challenge #297 - Loneliest Character

function lonliest(str)
{
  str = str.trim();
  let spaces = new Map();
  let curLetter = str[0];
  let spaceCount = 0;
  let biggestCount = 0;
  for(c of str)
  {
    if(c == ' ')
    {
      spaceCount++;
    }
    else
    {
      let sc = (spaces.has(curLetter)?spaces.get(curLetter):0)+spaceCount;
      spaces.set(curLetter, sc);
      if(sc > biggestCount)
      {
          biggestCount = sc;
      }
      curLetter = c;
      spaces.set(curLetter, spaceCount);
      spaceCount = 0;
    }
  }

  return [...spaces].filter(sc => sc[1] == biggestCount).map(sc => sc[0]);
}