181858

function solution(arr, k) {
  const set = new Set(arr);
  return set.size < k
    ? [...set, ...Array(k - set.size).fill(-1)]
    : [...set].slice(0, k);
}

const solution = (arr, k) => {
  const set = new Set(arr);
  const result = [...set].slice(0, k);
  while (result.length !== k) {
    result.push(-1);
  }
  return result;
};

function solution(arr, k) {
  return [...Array.from(new Set(arr)), ...new Array(k).fill(-1)].slice(0, k);
}