solves #2855: Minimum Right Shifts to Sort the Array in java

Author: anishLearnsToCode

README.md

@@ -854,7 +854,7 @@
 | 2839 | [Check if Strings Can be Made Equal With Operations I](https://leetcode.com/problems/check-if-strings-can-be-made-equal-with-operations-i)                             |                                                                         [![Java](assets/java.png)](src/CheckIfStringsCanBeMadeEqualWithOperationsI.java)                                                                         |                                                                                                                                   |
 | 2843 | [Count Symmetric Integers](https://leetcode.com/problems/count-symmetric-integers)                                                                                     |                                                                                   [![Java](assets/java.png)](src/CountSymmetricIntegers.java)                                                                                    |                                                                                                                                   |
 | 2848 | [Points That Intersect With Cars](https://leetcode.com/problems/points-that-intersect-with-cars)                                                                       |                                                                                 [![Java](assets/java.png)](src/PointsThatIntersectWithCars.java)                                                                                 |                                                                                                                                   |
-| 2855 | [Minimum Right Shifts to Sort the Array](https://leetcode.com/problems/minimum-right-shifts-to-sort-the-array)                                                         |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 2855 | [Minimum Right Shifts to Sort the Array](https://leetcode.com/problems/minimum-right-shifts-to-sort-the-array)                                                         |                                                                              [![Java](assets/java.png)](src/MinimumRightShiftsToSortTheArray.java)                                                                               |                                                                                                                                   |
 | 2859 | [Sum of Values at Indices With K Set Bits](https://leetcode.com/problems/sum-of-values-at-indices-with-k-set-bits)                                                     |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2833 | [Furthest Point From Origin](https://leetcode.com/problems/furthest-point-from-origin)                                                                                 |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2839 | [Check if Strings Can be Made Equal With Operations I](https://leetcode.com/problems/check-if-strings-can-be-made-equal-with-operations-i)                             |                                                                                                                                                                                                                                  |                                                                                                                                   |

src/MinimumRightShiftsToSortTheArray.java

@@ -0,0 +1,36 @@
+// https://leetcode.com/problems/minimum-right-shifts-to-sort-the-array
+// T: O(N)
+// S: O(1)
+
+import java.util.List;
+
+public class MinimumRightShiftsToSortTheArray {
+    public int minimumRightShifts(List<Integer> array) {
+        final int minElementIndex = getMinElementIndex(array);
+        if (!canSort(array, minElementIndex)) {
+            return -1;
+        }
+
+        return (array.size() - minElementIndex) % array.size();
+    }
+
+    private static boolean canSort(List<Integer> array, int minElementIndex) {
+        for (int i = (minElementIndex + 1) % array.size(), k = 0 ; k < array.size() - 1; k++, i = (i + 1) % array.size()) {
+            if (array.get(i) <= array.get((i - 1 + array.size()) % array.size())) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private static int getMinElementIndex(List<Integer> array) {
+        int minElement = Integer.MAX_VALUE, index = -1;
+        for (int i = 0 ; i < array.size() ; i++) {
+            if (array.get(i) < minElement) {
+                minElement = array.get(i);
+                index = i;
+            }
+        }
+        return index;
+    }
+}