public static List<Integer> largestPermutation(int k, List<Integer> arr) {
  int n = arr.size();
  int max = n;
  int[] indexMap = new int[max + 1];

  for (int i = 0; i < n; i++) {
    indexMap[arr.get(i)] = i;
  }

  for (int i = 0; i < n && k > 0; i++) {
    int currentValue = arr.get(i);
    int targetValue = n - i;
    if (currentValue != targetValue) {
      int targetIndex = indexMap[targetValue];
      arr.set(targetIndex, currentValue);
      arr.set(i, targetValue);
      indexMap[currentValue] = targetIndex;
      indexMap[targetValue] = i;
      k--;
    }
  }
  return arr;
}