Add array rotation utility using reversal algorithm

Author: Bhanubasyan

src/main/java/com/thealgorithms/others/ArrayRotation.java

@@ -0,0 +1,85 @@
+package com.thealgorithms.others;
+
+import java.util.Arrays;
+
+/**
+ * Array Rotation Utility
+ *
+ * Supports:
+ * 1. Left Rotation
+ * 2. Right Rotation
+ *
+ * Approach:
+ * Reversal Algorithm
+ *
+ * Time Complexity: O(n)
+ * Space Complexity: O(1)
+ */
+
+public class ArrayRotation {
+
+  /**
+   * Rotates the array to the right by k positions.
+   *
+   * @param nums the input array
+   * @param k    number of rotations
+   */
+
+  public static void rotateRight(int[] nums, int k) {
+
+    int n = nums.length;
+
+    if (n == 0) {
+      return;
+    }
+
+    k = k % n;
+
+    reverse(nums, 0, n - 1);
+    reverse(nums, 0, k - 1);
+    reverse(nums, k, n - 1);
+
+  }
+
+  /**
+   * Rotates the array to the left by k positions.
+   *
+   * @param nums the input array
+   * @param k    number of rotations
+   */
+
+  public static void rotateLeft(int[] nums, int k) {
+
+    int n = nums.length;
+
+    if (n == 0) {
+      return;
+    }
+
+    k = k % n;
+
+    reverse(nums, 0, k - 1);
+    reverse(nums, k, n - 1);
+    reverse(nums, 0, n - 1);
+  }
+
+  /**
+   * Reverses elements between start and end indices.
+   *
+   * @param nums  the input array
+   * @param start starting index
+   * @param end   ending index
+   */
+  private static void reverse(int[] nums, int start, int end) {
+
+    while (start < end) {
+
+      int temp = nums[start];
+      nums[start] = nums[end];
+      nums[end] = temp;
+
+      start++;
+      end--;
+    }
+  }
+}