import edu.gwu.stat.*;

public class MaxDifference1 {

  static double[] makeRandomArray (int length)
  {
    double[] A = new double [length];
    for (int i=0; i<length; i++) {
      A[i] = UniformRandom.uniform();
    }
    return A;
  }
  
  static void algorithm1 (double[] A)
  {
    // 1. Set the initial maximum to the difference between the first two: 
    double max = Math.abs (A[0] - A[1]);
    // 2. Record the actual values:
    double x = A[0],  y = A[1];

    // 3. Now compare each pair of numbers:
    for (int i=0; i<A.length-1; i++){
      for (int j=i+1; j<A.length; j++) {

        // 3.1 For each such pair, see if it's difference is larger
        //     than the current maximum.
        double diff = Math.abs (A[i] - A[j]);

        if (diff > max) {
          // 3.1.1 If so, record the new maximum and the values
          //       that achieved it.
          max = diff;
          x = A[i];
          y = A[j];
        } 

      } // inner-for
    } // outer-for

    // 4. Output:
    System.out.println ("Algorithm 1: the numbers: " + x + "," + y 
                        + " difference=" + max);
  }


  public static void main (String[] argv)
  {
    if ( (argv == null) || (argv.length == 0) ) {
      System.out.println ("Usage: java StringComparison <number-of-strings>");
      // System.exit(0);
    }

    try {
      int length = Integer.parseInt (argv[0]);
      double[] A = makeRandomArray (length);

      long startTime = System.currentTimeMillis();
      algorithm1 (A);
      double timeTaken = System.currentTimeMillis() - startTime;
      System.out.println ("Algorithm 1: timeTaken=" + timeTaken);

    }
    catch (Exception e) {
      System.out.println (e);
      //e.printStackTrace();
    }
  }


}