Added bubble sort

Author: rampatra

src/main/java/com/rampatra/arrays/sorting/BubbleSort.java

@@ -0,0 +1,49 @@
+package com.rampatra.arrays.sorting;
+
+import java.util.Arrays;
+
+/**
+ * @author rpatra16
+ * @since 03/11/2018
+ */
+public class BubbleSort {
+
+    /**
+     * In bubble sort, we start at the beginning of the array and swap
+     * the first two elements if the first is greater than the second.
+     * Then, we go to the next pair, and so on, continuously making sweeps
+     * of the array until it is sorted. In doing so, the smaller items
+     * slowly "bubble" up to the beginning of the list and in each inner
+     * iteration the largest element is sorted. Ergo, the inner loop runs
+     * until {@code length - i - 1} times. To learn more:
+     * {@see https://youtu.be/6Gv8vg0kcHc}
+     *
+     * @param ar
+     */
+    private static void bubbleSort(int[] ar) {
+        for (int i = 0; i < ar.length - 1; i++) {
+            for (int j = 0; j < ar.length - i - 1; j++) {
+                if (ar[j] > ar[j + 1]) {
+                    swap(ar, j, j + 1);
+                }
+            }
+        }
+    }
+
+    private static void swap(int[] ar, int i, int j) {
+        int temp = ar[i];
+        ar[i] = ar[j];
+        ar[j] = temp;
+    }
+
+    public static void main(String[] args) {
+        int[] ar = {2, 5, 1, 7, 8};
+        System.out.println(Arrays.toString(ar));
+        bubbleSort(ar);
+        System.out.println(Arrays.toString(ar));
+        ar = new int[]{7, 5, 1, 7, 8, 0, 23};
+        System.out.println(Arrays.toString(ar));
+        bubbleSort(ar);
+        System.out.println(Arrays.toString(ar));
+    }
+}