is_anagram.dart

void main() {
  bool result = isAnagram('iceman', 'cinemas');
  print(result);

}

bool isAnagram(String first, String second) {
  if (first.length != second.length) {
    return false;
  }

  var lookUp = <String, int>{};
  
  // (n + n ) = O(2n) = O(n)
  
  // n
  for (final c in first.split('')) {
    lookUp[c] = (lookUp[c] ?? 0) + 1;
  }

  // n 
  for (final c in second.split('')) {
    if (lookUp[c] == null) {
      return false;
    } else {
      lookUp[c] = lookUp[c]! - 1;
    }
  }
  return true;
}