// Chain of Responsibility
//   Minimum "pipes to" Total "pipes to" Average

abstract class PipeAndFilter {
  private PipeAndFilter next;
  public PipeAndFilter( PipeAndFilter n ) { next = n; }
  public void processNumber( int in ) {
    if (next != null) next.processNumber( in );
  }
  public void reportResults() {
    if (next != null) next.reportResults();
} }

class Minimum extends PipeAndFilter {
  private int min = 999;
  public Minimum( PipeAndFilter n ) { super( n ); }
  public void processNumber( int in ) {
    if (in < min) min = in;
    super.processNumber( in );
  }
  public void reportResults() {
    System.out.println( "minimum is " + min );
    super.reportResults();
} }

class Total extends PipeAndFilter {
  private int total = 0;
  public Total( PipeAndFilter n ) { super( n ); }
  public void processNumber( int in ) {
    total += in;
    super.processNumber( in );
  }
  public void reportResults() {
    System.out.println( "total is " + total );
    super.reportResults();
} }

class Average extends PipeAndFilter {
  private int total = 0, count = 0;
  public Average( PipeAndFilter n ) { super( n ); }
  public void processNumber( int in ) {
    total += in;
    count++;
    super.processNumber( in );
  }
  public void reportResults() {
    System.out.println( "average is " + ((double) total / count) );
    super.reportResults();
} }

public class ChainDemo {
  public static void main( String[] args ) {
    PipeAndFilter filters =
        new Minimum( new Total( new Average( null ) ) );
    int[] input = { 10, 1, 9, 2, 8, 3, 7, 4, 6, 5 };
    for (int i=0; i < input.length; i++)
      filters.processNumber( input[i] );
    filters.reportResults();
} }

// minimum is 1
// total is 55
// average is 5.5