public Permuter(int n){
  if (n < 0) {
    throw new IllegalArgumentException();
  }
  modulus=n;
  if (n == 1) {
    return;
  }
  multiplier=(int)Math.sqrt(n);
  while (gcd(multiplier,n) != 1) {
    if (++multiplier == n) {
      multiplier=1;
    }
  }
}

public Permuter ( int n ) { if ( n < 0 ) { throw new IllegalArgumentException ( ) ; } modulus = n ; if ( n == 1 ) { return ; } multiplier = ( int ) Math . sqrt ( n ) ; while ( gcd ( multiplier , n ) != 1 ) { if ( ++ multiplier == n ) { multiplier = 1 ; } } }
instantiates a new permuter .
