JavaAlgorithms/Maths/Median.java

package Maths;

import java.util.Arrays;

/** Wikipedia: https://en.wikipedia.org/wiki/Median */
public class Median {
  public static void main(String[] args) {
    assert median(new int[] {0}) == 0;
    assert median(new int[] {1, 2}) == 1.5;
    assert median(new int[] {4, 1, 3, 2}) == 2.5;
    assert median(new int[] {1, 3, 3, 6, 7, 8, 9}) == 6;
    assert median(new int[] {1, 2, 3, 4, 5, 6, 8, 9}) == 4.5;
  }

  /**
   * Calculate average median
   *
   * @param values number series
   * @return median of given {@code values}
   */
  public static double median(int[] values) {
    Arrays.sort(values);
    int length = values.length;
    return length % 2 == 0
        ? (values[length / 2] + values[length / 2 - 1]) / 2.0
        : values[length / 2];
  }
}