import java.util.*;

class LoopDemo {
    
    /* Return the sum of the numbers in `data`. */
    static double sum_v1( List<Double> data ) {
        if (data.isEmpty()) {
            return 0.0;
        }
        else {
            return data.get(0) + sum_v1(data.subList(1,data.size()));
        }
    }   

    
    
    static boolean foo( String s, int... nums ) {
      return (nums.length > 3);
      }
    
    
    
    /* Return the sum of the numbers in `data`. */    // <span id="sum_v2"/>
    static double sum_v2( List<Double> data ) {
        double sumSoFar = 0.0;
        while (!data.isEmpty()) {
            sumSoFar = sumSoFar + data.get(0);
            data = data.subList(1,data.size());
        }
        return sumSoFar;
    }
    

  
    /* Return the smallest of the numbers in `data`
     * (or the sentinel -inf.0 if empty -- arguably a poor choice).
     */    
    static double min_v2( List<Double> data ) {
        double minSoFar = data.get(0);
        while (!data.isEmpty()) {
            minSoFar = Math.min( minSoFar, data.get(0) );
            data = data.subList(1,data.size());
            }
        return minSoFar;
        }


        
        
        
    /* Return a list of numbers from n..1. */
    static List<Double> numsDown( int n ) {
      if (n==0) {
        return new LinkedList<Double>();
        }
      else {
        /* return numsDown(n-1).add(0, (double)n);*/
        List<Double> restNumsDown = numsDown(n-1);
        restNumsDown.add(0, (double)n);
        // `add` is a void method, so I can't combine with the preceding or following line.
        return restNumsDown;
        }
      }


    /* Return all the strings in `strs` appended with a space,
     * followed by "whoa".
     */
    static String stringAppendWhoa( List<String> strs ) {  
      String resultSoFar = "whoa";
      while (!strs.isEmpty()) {
        resultSoFar = strs.get(0) + " " + resultSoFar;
        strs = strs.subList(1,strs.size());
        }
      return resultSoFar;
      }

      
    public static void main( String[] args ) {
      System.out.println( foo( "hello", 2, 4, 7, 99, -1 ) );  
      System.out.println( foo( "hello", 2, 4 ) );  
        
        
      System.out.println( "Expect: 0.  Got: " + sum_v1( new ArrayList<Double>() ));
      System.out.println( "Expect: 12.  Got: "
                          + sum_v1(Arrays.asList( 5.0, 2.0, 4.0, 1.0 )) );
      System.out.println( "Expect: 0.  Got: " + sum_v2( new ArrayList<Double>() ));
      System.out.println( "Expect: 12.  Got: "
                          + sum_v2(Arrays.asList( 5.0, 2.0, 4.0, 1.0 )) );
      System.out.println( "Expect: \"hi bye aloha whoa\".  Got: "
                          + "\"" + stringAppendWhoa( Arrays.asList("hi","bye","aloha") ) + "\"" );
    }

      
      
}