/* DeleteCommandLine.java -- Array example program
   by Craig Persiko for CS 111A

   Reads from command line a series of numbers into an array, then deletes the one specified by the user
*/

import java.util.Scanner;

class DeleteCommandLine
{
  public static void main(String[] args)
  {
    Scanner scan = new Scanner(System.in);
    int[] nums;  // array reference variable
    int i, numEntries, numToDelete;
    
    // Make sure user entered at least one command line argument:
    if(args == null || args.length < 1)
    {
      System.out.println("usage: java DeleteCommandLine 5 4 2 8\nTo delete one of the numbers 5, 4, 2 and 8");
      return;
    }
    numEntries = args.length;
    nums = new int[numEntries];
    // convert command line into integers, and put into nums array.
    for(i=0; i < numEntries; i++)
      nums[i] = Integer.parseInt(args[i]);

    // now nums array is filled with numbers from command line
  
    System.out.println("Here is your array of numbers:");
    outputArray(nums, numEntries);
    
    System.out.print("Which number do you want to remove? ");
    numToDelete = scan.nextInt();
    
    for(i=0; i < numEntries; i++)
      if(nums[i] == numToDelete)
      {
        deleteFromArray(nums, i);  // delete element number i from the array
        numEntries--;  // now we have one fewer element to output
        // in case there is another copy of numToDelete in the array, we'll keep looping.
        // since we just moved the following element back to element i, we need to check i again.
        i--;
      }

    System.out.println("Here is the array with " + numToDelete + " removed:");
    outputArray(nums, numEntries);
  }

  // output the array, separated by commas:
  public static void outputArray(int[] nums, int numElements)
  {   
    System.out.print(nums[0]); // output first value
    // output rest of array with commas:
    for (int i = 1; i < numElements; i++)
      System.out.print(", " + nums[i]);
    System.out.println();
  }

  // remove element indexToDelete from the array a
  public static void deleteFromArray(int[] a, int indexToDelete)
  {
    for(int i=indexToDelete; i < a.length-1; i++)
      a[i] = a[i+1];
  }

}

/*  Sample Output:

[cpersiko@fog cs111a]$ javac DeleteCommandLine.java 
[cpersiko@fog cs111a]$ java DeleteCommandLine
usage: java DeleteCommandLine 5 4 2 8
To delete one of the numbers 5, 4, 2 and 8
[cpersiko@fog cs111a]$ java DeleteCommandLine 1 2 3 8 9 10
Here is your array of numbers:
1, 2, 3, 8, 9, 10
Which number do you want to remove? 2
Here is the array with 2 removed:
1, 3, 8, 9, 10
[cpersiko@fog cs111a]$ java DeleteCommandLine 1 2 3 8 9 10 3 3 5 6
Here is your array of numbers:
1, 2, 3, 8, 9, 10, 3, 3, 5, 6
Which number do you want to remove? 3
Here is the array with 3 removed:
1, 2, 8, 9, 10, 5, 6
[cpersiko@fog cs111a]$ 

*/