JavaAlgorithms/Sorts/SortUtils.java

package Sorts;

import java.util.Arrays;
import java.util.List;

/**
 * The class contains util methods
 *
 * @author Podshivalov Nikita (https://github.com/nikitap492)
 */
final class SortUtils {

  /**
   * Helper method for swapping places in array
   *
   * @param array The array which elements we want to swap
   * @param idx index of the first element
   * @param idy index of the second element
   */
  static <T> boolean swap(T[] array, int idx, int idy) {
    T swap = array[idx];
    array[idx] = array[idy];
    array[idy] = swap;
    return true;
  }

  /**
   * This method checks if first element is less than the other element
   *
   * @param v first element
   * @param w second element
   * @return true if the first element is less than the second element
   */
  static <T extends Comparable<T>> boolean less(T v, T w) {
    return v.compareTo(w) < 0;
  }

  /**
   * This method checks if first element is greater than the other element
   *
   * @param v first element
   * @param w second element
   * @return true if the first element is greater than the second element
   */
  static <T extends Comparable<T>> boolean greater(T v, T w) {
    return v.compareTo(w) > 0;
  }

  /**
   * This method checks if first element is greater than or equal the other element
   *
   * @param v first element
   * @param w second element
   * @return true if the first element is greater than or equal the second element
   */
  static <T extends Comparable<T>> boolean greaterOrEqual(T v, T w) {
    return v.compareTo(w) >= 0;
  }

  /**
   * Prints a list
   *
   * @param toPrint - a list which should be printed
   */
  static void print(List<?> toPrint) {
    toPrint.stream().map(Object::toString).map(str -> str + " ").forEach(System.out::print);

    System.out.println();
  }

  /**
   * Prints an array
   *
   * @param toPrint - an array which should be printed
   */
  static void print(Object[] toPrint) {
    System.out.println(Arrays.toString(toPrint));
  }

  /**
   * Swaps all position from {@param left} to @{@param right} for {@param array}
   *
   * @param array is an array
   * @param left is a left flip border of the array
   * @param right is a right flip border of the array
   */
  static <T extends Comparable<T>> void flip(T[] array, int left, int right) {
    while (left <= right) {
      swap(array, left++, right--);
    }
  }
}