Click here to download c24/LLOld.java.

import java.util.*;

interface Sum { void add(Number x); }

class FloatSum implements Sum {
  float val = 0;
  public void add(Number x) 
  { val += ((Float)x).floatValue(); }
  public String toString() { return String.valueOf(val); }
}

class IntSum implements Sum {
  int val = 0;
  public void add(Number x) 
  { val += ((Integer)x).intValue(); }
  public String toString() { return String.valueOf(val); }
}

class LLOld {
  Number data;
  LLOld next;

  LLOld(Number d, LLOld n) { data = d; next = n; }

  Sum printAndSum(Sum summer) {
    System.out.println(data);
    summer.add(data);
    if (next != null) next.printAndSum(summer);
    return summer;
  }

  public static void main(String[] args) {
    LLOld flist = null;
    LLOld ilist = null;

    Scanner in = new Scanner(System.in);
    while (in.hasNextDouble()) {
      double d = in.nextDouble();
      flist = new LLOld(Float.valueOf((float)d), flist);
      ilist = new LLOld(Integer.valueOf((int)d), ilist);
    }

    System.out.println("Floating sum: " + 
      flist.printAndSum(new FloatSum()) + "\n");
    System.out.println("Integer sum: " + 
      ilist.printAndSum(new IntSum()) + "\n");
  }
}