ArrayExamples.java

public class ArrayExamples {

  // Changes the input array to be in reversed order
  static void reverseInPlace(int[] arr) {
    int[] old = new int[arr.length];
    for (int i = 0; i < arr.length; i++) {
      old[i] = arr[i];
    }
    for (int i = 0; i < arr.length; i += 1) {
      arr[i] = old[arr.length - i - 1];
    }
  }

  // Returns a *new* array with all the elements of the input array in reversed
  // order
  static int[] reversed(int[] arr) {
    int[] newArray = new int[arr.length];
    for (int i = 0; i < arr.length; i += 1) {
      newArray[i] = arr[arr.length - i - 1];
    }
    return newArray;
  }

  // Averages the numbers in the array (takes the mean), but leaves out the
  // lowest number when calculating. Returns 0 if there are no elements or just
  // 1 element in the array
  static double averageWithoutLowest(double[] arr) {
    if (arr.length < 2) {
      return 0.0;
    }
    double lowest = arr[0];
    for (double num : arr) {
      if (num < lowest) {
        lowest = num;
      }
    }
    double sum = 0;
    for (double num : arr) {
      if (num != lowest) {
        sum += num;
      }
    }
    return sum / (arr.length - 1);
  }

}