// Introduction to Software Testing
// Authors: Paul Ammann & Jeff Offutt
// Chapter 1; page 13
// Can be run from command line
// See FindLastTest.java for JUnit tests

import java.io.*;

public class FindLast
{
  /**
    * Find last index of element
    * 
    *  @param x array to search
    *  @param y value to look for
    *  @return last index of y in x; -1 if absent
    *  @throws NullPointerException if x is null
    */
   public static int findLast (int[] x, int y)
   { 
      // As the example in the book points out, this loop should end at 0.
      for (int i=x.length-1; i > 0; i--)
      {
         if (x[i] == y) 
         {
            return i;
         }
      }
      return -1;
   }

   public static void main (String []argv)
   {  // Driver method for findLast
      // Read an array and an integer from standard input, call findLast()
      int integer = 0;
      int []inArr = new int [argv.length];
      if (argv.length == 0)
      {
         System.out.println ("Usage: java FindLast v1 [v2] [v3] ... ");
         return;
      }
   
      for (int i = 0; i< argv.length; i++)
      {
         try
         {
            inArr [i] = Integer.parseInt (argv[i]);
         }
         catch (NumberFormatException e)
         {
            System.out.println ("Entry must be a integer, using 1.");
            inArr [i] = 1;
         }
      }
      System.out.println ("Enter an integer you want to find: ");
      integer = getN();
   
      System.out.println ("The index of the last element equal to " + integer + " is: " + findLast (inArr, integer));
   }
   
   // ====================================
   // Read (or choose) an integer
   private static int getN ()
   {
      int inputInt = 1;
      BufferedReader in = new BufferedReader (new InputStreamReader (System.in));
      String inStr;
   
      try
      {
         inStr    = in.readLine ();
         inputInt = Integer.parseInt(inStr);
      }
      catch (IOException e)
      {
         System.out.println ("Could not read input, choosing 1.");
      }
      catch (NumberFormatException e)
      {
         System.out.println ("Entry must be a number, choosing 1.");
      }
   
      return (inputInt);
   }  // end getN
}