Add bubble sort algorithm

README.md

@@ -10,6 +10,7 @@ notations were taken from the  [Big O Cheatsheet](http://bigocheatsheet.com/)
 
 Algorithm|Implementation|Tests|Worst Time Complexity|Worst Space Complexity
 -----|-----|-----|-----|-----
+[Bubble Sort](https://en.wikipedia.org/wiki/Bubble_sort)|[BubbleSort.java](sorting/src/main/java/com/wbrawner/algorithms/sorting/BubbleSort.java)|[ParameterizedBubbleSortTest.java](sorting/src/test/java/com/wbrawner/algorithms/sorting/ParameterizedBubbleSortTest.java)|O(n²)|O(1)
 [Insertion Sort](https://en.wikipedia.org/wiki/Insertion_sort)|[InsertionSort.java](sorting/src/main/java/com/wbrawner/algorithms/sorting/InsertionSort.java)|[ParameterizedInsertionSortTest.java](sorting/src/test/java/com/wbrawner/algorithms/sorting/ParameterizedInsertionSortTest.java)|O(n²)|O(1)
 [Merge Sort](https://en.wikipedia.org/wiki/Merge_sort)|[MergeSort.java](sorting/src/main/java/com/wbrawner/algorithms/sorting/MergeSort.java)|[ParameterizedMergeSortTest.java](sorting/src/test/java/com/wbrawner/algorithms/sorting/ParameterizedMergeSortTest.java)|O(n log(n))|O(n)
 

sorting/src/main/java/com/wbrawner/algorithms/sorting/BubbleSort.java

@@ -0,0 +1,36 @@
+package com.wbrawner.algorithms.sorting;
+
+/**
+ * The Bubble Sort algorithm modifies an array in place, continuously
+ * looping through the array and swapping elements that are unsorted until no
+ * elements have been swapped.
+ */
+public class BubbleSort {
+    /**
+     * Sort a given array of ints using the Bubble Sort algorithm
+     *
+     * @param array an unsorted array of ints
+     * @return a sorted array of ints
+     */
+    public static int[] sort(int[] array) {
+        // An empty array or array with only a single value can't be sorted
+        if (array.length < 2) {
+            return array;
+        }
+
+        boolean swapsMade;
+        do {
+            swapsMade = false;
+            for (int i = 1; i < array.length; i++) {
+                if (array[i] < array[i - 1]) {
+                    int currentValue = array[i];
+                    array[i] = array[i - 1];
+                    array[i - 1] = currentValue;
+                    swapsMade = true;
+                }
+            }
+        } while (swapsMade);
+
+        return array;
+    }
+}

sorting/src/test/java/com/wbrawner/algorithms/sorting/ParameterizedBubbleSortTest.java

@@ -0,0 +1,31 @@
+package com.wbrawner.algorithms.sorting;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import static org.junit.Assert.assertArrayEquals;
+
+@RunWith(Parameterized.class)
+public class ParameterizedBubbleSortTest {
+
+
+    @Parameterized.Parameter(1)
+    public int[] sorted;
+
+    @Parameterized.Parameter()
+    public int[] unsorted;
+
+    @Test
+    public void sortTest() {
+        assertArrayEquals(
+                sorted,
+                BubbleSort.sort(unsorted)
+        );
+    }
+
+    @Parameterized.Parameters
+    public static int[][][] getData() {
+        return SortData.get();
+    }
+}

sorting/src/test/java/com/wbrawner/algorithms/sorting/SortData.java

@@ -51,6 +51,20 @@ public class SortData {
                         // Sorted values
                         new int[]{1}
                 },
+                // Seventh data set - a reverse sorted array
+                new int[][]{
+                        // Unsorted values
+                        new int[]{100, 90, 80, 70, 60, 50, 40, 30, 20, 10, 0},
+                        // Sorted values
+                        new int[]{0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100}
+                },
+                // Eight data set - an already sorted array
+                new int[][]{
+                        // Unsorted values
+                        new int[]{0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100},
+                        // Sorted values
+                        new int[]{0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100}
+                },
         };
     }
 }