Fixed checkstyle and docs (TheAlgorithms#2035)

* Update bubble sort algorithm * fixed checkstyle * Formatted with Google Java Formatter Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>

Author: realDuYuanChao

.github/workflows/checkstyle.yml

@@ -1,6 +1,6 @@
 name: Code Formatter
 
-on: [push]
+on: [push, pull_request]
 jobs:
  format:
  runs-on: ubuntu-latest

Sorts/BubbleSort.java

@@ -8,10 +8,13 @@
  * @see SortAlgorithm
  */
 class BubbleSort implements SortAlgorithm {
+
  /**
- * This method implements the Generic Bubble Sort
+ * Implements generic bubble sort algorithm.
  *
- * @param array The array to be sorted Sorts the array in ascending order
+ * @param array the array to be sorted.
+ * @param <T> the type of elements in the array.
+ * @return the sorted array.
  */
  @Override
  public <T extends Comparable<T>> T[] sort(T[] array) {
@@ -30,20 +33,23 @@ public <T extends Comparable<T>> T[] sort(T[] array) {
  return array;
  }
 
- // Driver Program
+ /** Driver Code */
  public static void main(String[] args) {
 
- // Integer Input
  Integer[] integers = {4, 23, 6, 78, 1, 54, 231, 9, 12};
  BubbleSort bubbleSort = new BubbleSort();
  bubbleSort.sort(integers);
 
- // Output => 1, 4, 6, 9, 12, 23, 54, 78, 231
- print(integers);
+ for (int i = 0; i < integers.length - 1; ++i) {
+ assert integers[i] <= integers[i + 1];
+ }
+ print(integers); /* output: [1, 4, 6, 9, 12, 23, 54, 78, 231] */
 
- // String Input
  String[] strings = {"c", "a", "e", "b", "d"};
- // Output => a, b, c, d, e
- print(bubbleSort.sort(strings));
+ bubbleSort.sort(strings);
+ for (int i = 0; i < strings.length - 1; i++) {
+ assert strings[i].compareTo(strings[i + 1]) <= 0;
+ }
+ print(bubbleSort.sort(strings)); /* output: [a, b, c, d, e] */
  }
 }