JavaAlgorithms/Sorts/InsertionSort.java

package Sorts;

import static Sorts.SortUtils.less;
import static Sorts.SortUtils.print;

/**
 * @author Varun Upadhyay (https://github.com/varunu28)
 * @author Podshivalov Nikita (https://github.com/nikitap492)
 */
class InsertionSort implements SortAlgorithm {

  /**
   * This method implements the Generic Insertion Sort Sorts the array in increasing order
   *
   * @param array The array to be sorted
   */
  @Override
  public <T extends Comparable<T>> T[] sort(T[] array) {
    for (int j = 1; j < array.length; j++) {

      // Picking up the key(Card)
      T key = array[j];
      int i = j - 1;

      while (i >= 0 && less(key, array[i])) {
        array[i + 1] = array[i];
        i--;
      }
      // Placing the key (Card) at its correct position in the sorted subarray
      array[i + 1] = key;
    }
    return array;
  }

  // Driver Program
  public static void main(String[] args) {
    // Integer Input
    Integer[] integers = {4, 23, 6, 78, 1, 54, 231, 9, 12};

    InsertionSort sort = new InsertionSort();

    sort.sort(integers);

    // Output => 1 4 6 9 12 23 54 78 231
    print(integers);

    // String Input
    String[] strings = {"c", "a", "e", "b", "d"};

    sort.sort(strings);

    // Output => a	b	c	d	e
    print(strings);
  }
}