/**
  * Copyright (c): Uwe Schmidt, FH Wedel
  *
  * You may study, modify and distribute this source code
  * FOR NON-COMMERCIAL PURPOSES ONLY.
  * This copyright message has to remain unchanged.
  *
  * Note that this document is provided 'as is',
  * WITHOUT WARRANTY of any kind either expressed or implied.
  */

/**
  *
  * another variant of Merge
  */

//--------------------

public
class Merge1 extends Sequence {
  private
  long hd2;

  private
  Sequence s1, s2;

  public
  Merge1(Sequence s1, Sequence s2) {

    this.s1 = s1;
    this.s2 = s2;

    hd2 = s2.next();
  }

  public
  long next() {
    long res;

    res = s1.next();
    if ( res > hd2 ) {
	// swap sequences and lookahead

	Sequence s3;
	s3 = s1;
	s1 = s2;
	s2 = s3;

	long hd1;
	hd1 = res;
	res = hd2;
	hd2 = hd1;
    }

    return res;
  }
}

//--------------------