fineSwapScreening.dart

void main() {
  int resultFindNthSmallest;
  int resultsumOf;
  int resultPersistance;

  resultFindNthSmallest = findNthSmallest([6, 2, 9, 1], 2);
  print("findNthSmallest([6, 2, 9, 1], 2) =$resultFindNthSmallest");
  resultFindNthSmallest =
      findNthSmallest([57, 3, 0, -5, 2, 67, 32, 9, 1, 2], 5);
  print(
      "findNthSmallest([57, 3, 0, -5, 2, 67, 32, 9, 1, 2], 5) = $resultFindNthSmallest");
  resultsumOf = sumOf([9, 34, -23, 0, 4, 8]);
  print("sumOf([9, 34, -23, 0, 4, 8]) =$resultsumOf");
  resultsumOf = sumOf([901, 492, -10223, 3791, 243, 2]);
  print("sumOf([901, 492, -10223, 3791, 243, 2]) =$resultsumOf");
  resultPersistance = multiplicativePersistenceOf(489);
  print("multiplicativePersistenceOf(489) =$resultPersistance");
  resultPersistance = multiplicativePersistenceOf(912);
  print("multiplicativePersistenceOf(912) =$resultPersistance");
}

int findNthSmallest(List<int> integers, int nth) {
  assert(integers.length >= nth);
  int result = integers[0];
  for(var i=0;i<integers.length;i++){
    if (integers[i] < result) result = integers[i];
  }
  return result;
}

int sumOf(List<int> integers) {
  int result = 0;
  integers.map((e) => result = result + e).toList();
  return result;
}

int multiplicativePersistenceOf(int value) {
  assert(value > 0);

  int temp = value;
  int result = 0;
  while (getLength(temp) > 1) {
    temp = multiply(temp);
    result++;
  }
  return result;
}

getLength(number) {
  return "$number".length;
}

multiply(int number) {
  int product = 1;
  List<int> numberArray = number.toString().split("").map(int.parse).toList();
   numberArray.map((e) => product = product * e).toList();
  return product;
}