/**
 * Utilities for finding interesting facts about arrays of integers.
 *
 * @author Samuel A. Rebelsky
 * @author Carla Caffeinated
 * @author Carl Caffeinated
 * @version 1.0 of October 1999
 */
public class DifferenceComputer {
  /**
   * Determine the greatest difference between any pair of values
   * in the an array of integers.
   * Pre: The array is nonempty.
   * Pre: The greatest difference is less than the maximum integer.
   * Post: Returns the largest |values[i]-values[j]|.
   */
  public int greatestDifference(int[] values) {
    int estimate = 0;
    int difference;
    // For each value, values[i], in the collection
    for (int i = 0; i < values.length; ++i) {
      // For each value, values[j], in the collection
      for (int j = 0; j < values.length; ++j) {
        // Determine the difference between the two values
        difference = Math.abs(values[i]-values[j]) ;
        // If it's bigger than the biggest difference so far then
        if (difference > estimate) {
          // Update our estimate of the biggest difference
          estimate = difference;
        }
      } // for j
    } // for i
    return estimate;
  } // greatestDifference(int[] values)
  
  /**
   * Determine the greatest difference between any pair of values
   * in the an array of integers.
   * Pre: The array is nonempty.
   * Pre: The greatest difference is less than the maximum integer.
   * Post: Returns the largest |values[i]-values[j]|.
   */
  public int leastDifference(int[] values) {
    int estimate = Integer.MAX_VALUE;
    int difference;
    // For each value, values[i], in the collection
    for (int i = 0; i < values.length; ++i) {
      // For each value, values[j], in the collection
      for (int j = 0; j < values.length; ++j) {
        // If the two values are not the same
        if (values[i] != values[j]) {
          // Determine the difference between the two values
          difference = Math.abs(values[i]-values[j]) ;
          // If it's smaller than the least difference so far then
          if (difference < estimate) {
            // Update our estimate of the least difference
            estimate = difference;
          }
        } // if the two values are different
      } // for j
    } // for i
    return estimate;
  } // leastDifference(int[] values)
} // class DifferenceComputer