import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Arrays;

class Change
{
  /*
   * for easier printing
   */
  public static void p(Object o) {System.out.print(o);}
  public static void pl(Object o) {System.out.println(o);}
  
  /*
   * main method
   */
  public static void main( String[] args )
  {
    // You should use the code below and the examples
    //   miss_example
    //   knap_example
    
    // You'll want to 
    //
    // (1) read in the file name
    // (2) read in the change file data
    //     first, the number of denominations
    //     then, the denominations themselves
    // (3) ask for an amount to make change for
    // (4) then, compute the minimum solution
    //     print the minimum number of coins
    //     and print the coins used
    
    Scanner kbd = new Scanner(System.in);
    p( "Enter a filename such as coins1.txt: " );
    String filename = kbd.nextLine();
    filename = filename.trim();
    pl("Now trying to open " + filename);
    
    Scanner file = null;
    try { // in case the file's not there
      file = new Scanner(new File(filename));
    } catch (FileNotFoundException e) {
      pl("File " + filename + " not found.");
      pl( e );
    }
    
    // get integer at the start of the file:
    int num_coins = file.nextInt();
    pl("Read the # of coins = " + num_coins);
    
    // create an array, coins, to hold the coins:
    int[] coins = new int[num_coins];
    
    // here, you'll need to loop in order to read each coin in...
    
    // It's useful for debugging to be able to print an array 
    pl("The array, coins, is " + Arrays.toString( coins ));
    
    //
    // here's the DP - all in main is OK or, if you prefer, in another function
    //
    
    pl("Input the value to make change for: ");
    int amt = kbd.nextInt(); // this will crash if it's not an int - that's OK.
    pl("Solution:");
    pl("I don't know -- yet!");
  }
}