Array of int rotation to left and right by d elements

Author: Antesh Sharma

src/main/java/com/antesh/problems/ArrayRotation.java

@@ -0,0 +1,55 @@
+package com.antesh.problems;
+
+import java.util.Arrays;
+
+/*  Write a function rotate(ar[], d, n) that rotates arr[] of size n by d elements to right
+*
+*   Sample 1: { 1, 2, 3, 4, 5, 6, 7 }, d = 2, rotate right
+*   output 1: { 6, 7, 1, 2, 3, 4, 5 }
+*
+*   Sample 1: { 1, 2, 3, 4, 5, 6, 7 }, d = 2, rotate left
+*   output 1: { 3, 4, 5, 6, 7, 1, 2 }
+ * */
+public class ArrayRotation {
+
+    //TC: O(n*d)
+    public static void rotateRight(int[] arr, int d) {
+        if (arr == null || arr.length == 0) {
+            return;
+        }
+        int n = arr.length;
+        int j = 0;
+        while (j < d) {
+            int temp = arr[n - 1];
+            for (int i = 0; i < n; i++) {
+                int current = arr[i];
+                arr[i] = temp;
+                temp = current;
+
+            }
+            j++;
+        }
+    }
+
+    public static void rotateLeft(int[] arr, int d) {
+        if (arr == null || arr.length == 0) {
+            return;
+        }
+        int n = arr.length;
+        rotateRight(arr, n-d);
+    }
+
+    public static void main(String[] args) {
+        int[] arr = {1, 2, 3, 4, 5, 6, 7};
+        rotateRight(arr, 1);
+        System.out.println(Arrays.toString(arr));
+
+        int[] arr1 = {1, 2, 3, 4, 5, 6, 7};
+        rotateRight(arr1, 2);
+        System.out.println(Arrays.toString(arr1));
+
+        int[] arr2 = {1, 2, 3, 4, 5, 6, 7};
+        rotateLeft(arr2, 2);
+        System.out.println(Arrays.toString(arr2));
+    }
+}