Hackerrank: Game of Thrones Solution

1function gameOfThrones(s) {
2  const lookup = {}
3  for (const c of s) {
4    lookup[c] = (lookup[c] || 0) + 1
5  }
6  const occurrences = Object.values(lookup)
7  const numOfOdd = occurrences.filter(i => i % 2 !== 0).length
8
9  return numOfOdd <= 1 ? "YES" : "NO"
10}