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file:PlaygroundNumUnique.java [source]
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package algs13;
import java.text.DecimalFormat;
import stdlib.*;
public class PlaygroundNumUnique {
  private Node first;
  static class Node { 
    public double item; 
    public Node next; 
    public Node (double item, Node next) { 
      this.item = item; 
      this.next = next; 
    }
  }
  
  /** Number of unique items, assuming the list is sorted */
  public int numUnique() {
    return StdRandom.uniform (100); //TODO: fix this
  }

  public static void main1 (String[] args) {
    Trace.showBuiltInObjects(true);
    Trace.drawStepsOfMethod ("numUnique");
    Trace.run ();
    PlaygroundNumUnique list1 = PlaygroundNumUnique.from ("11 21 21 21 31");
    int result1 = list1.numUnique ();
    Trace.draw();
    StdOut.println ("result: " + result1);
  }

  public static void main (String[] args) {
    testNumUnique(4, "11 21 21 21 31 41 41 41 41");
    testNumUnique(1, "11 11 11 11");
    testNumUnique(4, "11 21 31 41");
    testNumUnique(4, "11 11 11 21 31 31 31 31 41");
    testNumUnique(4, "11 11 21 21 21 31 31 41 41 41 41");
    testNumUnique(8, "11 11 11 11 21 31 41 41 41 41 41 51 51 61 71 81 81");
    testNumUnique(8, "11 21 31 41 41 41 41 41 51 51 61 71 81");
    testNumUnique(7, "11 11 11 11 21 31 41 41 41 41 41 51 51 61 71");
    testNumUnique(7, "11 21 31 41 41 41 41 41 51 51 61 71");
    testNumUnique(8, "-81 -81 -81 -81 -71 -61 -51 -51 -51 -51 -41 -41 -31 -21 -11 -11 -11");
    testNumUnique(3, "-11 -11 -11 0 0 11 11 11");
    testNumUnique(2, "0 11 11 11");
    testNumUnique(2, "-Infinity 11 11 11");
    testNumUnique(2, "11 11 11 Infinity");
    testNumUnique(1, "11 11");
    testNumUnique(1, "11");
    testNumUnique(0, "");
    
    StdOut.println ("Finished tests");
  }

  private static void testNumUnique (int expected, String sList) {
    PlaygroundNumUnique list = PlaygroundNumUnique.from (sList); 
    String sStart = list.toString ();
    int actual = list.numUnique ();
    if (expected != actual) {
      StdOut.format ("Failed: Expecting [%d] Actual [%d] with argument %s\n", expected, actual, list);
    }
    String sEnd = list.toString ();
    if (! sStart.equals (sEnd)) {
      StdOut.format ("Failed %s.numUnique(): List changed to %s\n", sStart, sEnd);
    }
  }

  /* ToString method to print */
  public String toString () { 
    // Use DecimalFormat #.### rather than String.format 0.3f to leave off trailing zeroes
    DecimalFormat format = new DecimalFormat ("#.###");
    StringBuilder result = new StringBuilder ("[ ");
    for (Node x = first; x != null; x = x.next) {
      result.append (format.format (x.item));
      result.append (" ");
    }
    result.append ("]");
    return result.toString ();
  }

  /* Method to create lists */
  public static PlaygroundNumUnique from(String s) {
    PlaygroundNumUnique result = new PlaygroundNumUnique ();
    if ("".equals (s)) return result;

    Node first = null;
    String[] nums = s.split (" ");
    for (int i = nums.length-1; i >= 0; i--) {
      try { 
        double num = Double.parseDouble (nums[i]); 
        first = new Node (num, first);      
      } catch (NumberFormatException e) {
        throw new IllegalArgumentException (String.format ("Bad argument \"%s\": could not parse \"%s\" as a double", s, nums[i]));
      }
    }
    result.first = first;
    return result;
  }
}

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