// Program to test solutions to problem #6 on the cse143 midterm, summer 2019.
// Fill in your solution to retainAll, then compile and run the program.

import java.util.*;

class ArrayIntList {
   public void retainAll(Set<Integer> s) {
      // fill in your solution here
      // you can change the name of the parameter
   }

   // this is the sample solution
   public void retainAll2(Set<Integer> s) {
      for (int i = 0; i < size; i++) {
         if (!s.contains(elementData[i])) {
            for (int j = i; j < size - 1; j++) {
               elementData[j] = elementData[j + 1];
            }
            size--;
            i--;
         }
      }
   }

   private int[] elementData; // list of integers
   private int size;          // current number of elements in the list

   // post: constructs an empty list of default capacity
   public ArrayIntList(int capacity) {
      elementData = new int[capacity];
      size = 0;
   }

   // post: creates a comma-separated, bracketed version of the list
   public String toString() {
      if (size == 0) {
         return "[]";
      } else {
         String result = "[" + elementData[0];
         for (int i = 1; i < size; i++) {
            result += ", " + elementData[i];
         }
         result += "]";
         return result;
      }
   }

   // post: appends the given value to the end of the list
   public void add(int value) {
      elementData[size] = value;
      size++;
   }
}

public class Test6 {
   private static int passCount, failCount;

   public static void main(String[] args) {
      int[] data = {23, 34, -6, 98, -12, 7, 44, 23, 67, 23, 12};
      Integer[] set = {6, 8, 12, 15, 17, 23, 44};
      test(data, set);

      data = new int[]{};
      set  = new Integer[]{};
      test(data, set);

      data = new int[]{1, 2, 4, 5, 7, 8};
      set  = new Integer[]{};
      test(data, set);

      data = new int[]{};
      set  = new Integer[]{1, 2, 5, 6, 7, 8};
      test(data, set);

      data = new int[]{1, 2, 3, 4, 5};
      set  = new Integer[]{6, 7, 8, 9, 10};
      test(data, set);

      data = new int[]{1, 2, 3, 4};
      set  = new Integer[]{1, 2, 3, 4};
      test(data, set);

      data = new int[]{1, 2, 3, 4, 1, 1, 2, 3, 4, 1};
      set  = new Integer[]{1, 2, 3, 4};
      test(data, set);

      System.out.println("tests passed: " + passCount);
      System.out.println("tests failed: " + failCount);
   }

   public static void test(int[] data, Integer[] set) {
      ArrayIntList list1 = new ArrayIntList(data.length);
      ArrayIntList list2 = new ArrayIntList(data.length);
      Set<Integer> s = new TreeSet<Integer>();
      s.addAll(Arrays.asList(set));

      for (int n : data) {
         list1.add(n);
         list2.add(n);
      }

      System.out.println("testing...");
      System.out.println("   list = " + list1);
      System.out.println("   set  = " + s);

      try {
         list1.retainAll(s);
         list2.retainAll2(s);
         if (list1.toString().equals(list2.toString())) {
            passCount++;
            System.out.println("passed");
         } else {
            failCount++;
            System.out.println("failed");
         }
      } catch (RuntimeException e) {
         int line = e.getStackTrace()[2].getLineNumber();
         System.out.println("    threw " + e + " at line #" + line);
         failCount++;
         System.out.println("failed");
      }
      System.out.println();
   }
}