Update StalinSort.java

Author: anant-jain01

src/main/java/com/thealgorithms/sorts/StalinSort.java

@@ -1,66 +1,41 @@
 package com.thealgorithms.sorts;
 
-import static org.junit.jupiter.api.Assertions.assertArrayEquals;
-
-import org.junit.jupiter.api.Test;
-
-public class StalinSortTest {
-
-    private StalinSort stalinSort = new StalinSort();
-
-    @Test
-    public void stalinSortEmptyArray() {
-        Integer[] inputArray = {};
-        Integer[] outputArray = stalinSort.sort(inputArray);
-        Integer[] expectedOutput = {};
-        assertArrayEquals(outputArray, expectedOutput);
-    }
-
-    @Test
-    public void stalinSortSingleIntegerArray() {
-        Integer[] inputArray = {4};
-        Integer[] outputArray = stalinSort.sort(inputArray);
-        Integer[] expectedOutput = {4};
-        assertArrayEquals(outputArray, expectedOutput);
+/**
+ * @author Anant Jain (https://github.com/anant-jain01)
+ * @see https://medium.com/@kaweendra/the-ultimate-sorting-algorithm-6513d6968420
+ */
+public class StalinSort implements SortAlgorithm {
+
+    public <T extends Comparable<T>> T[] sort(T[] array) {
+        int currentIndex = 0;
+
+        for (int i = 1; i < array.length; i++) {
+            if (array[i].compareTo(array[currentIndex]) >= 0) {
+                currentIndex++;
+                array[currentIndex] = array[i];
+            }
+        }
+
+        // Create a result array with sorted elements
+        T[] result = (T[]) new Comparable[currentIndex + 1];
+        System.arraycopy(array, 0, result, 0, currentIndex + 1);
+
+        return result;
     }
 
-    @Test
-    public void stalinSortSingleStringArray() {
-        String[] inputArray = {"s"};
-        String[] outputArray = stalinSort.sort(inputArray);
-        String[] expectedOutput = {"s"};
-        assertArrayEquals(outputArray, expectedOutput);
-    }
+    // Driver Program
+    public static void main(String[] args) {
+        // Integer Input
+        Integer[] integers = {4, 23, 6, 78, 1, 54, 231, 9, 12};
 
-    @Test
-    public void stalinSortNonDuplicateIntegerArray() {
-        Integer[] inputArray = {6, -1, 99, 27, -15, 23, -36};
-        Integer[] outputArray = stalinSort.sort(inputArray);
-        Integer[] expectedOutput = {-36, -15, -1, 6, 23, 27, 99};
-        assertArrayEquals(outputArray, expectedOutput);
-    }
+        StalinSort stalinSort = new StalinSort();
 
-    @Test
-    public void stalinSortDuplicateIntegerArray() {
-        Integer[] inputArray = {6, -1, 27, -15, 23, 27, -36, 23};
-        Integer[] outputArray = stalinSort.sort(inputArray);
-        Integer[] expectedOutput = {-36, -15, -1, 6, 23, 23, 27, 27};
-        assertArrayEquals(outputArray, expectedOutput);
-    }
+        // print a sorted array
+        SortUtils.print(stalinSort.sort(integers));
 
-    @Test
-    public void stalinSortNonDuplicateStringArray() {
-        String[] inputArray = {"s", "b", "k", "a", "d", "c", "h"};
-        String[] outputArray = stalinSort.sort(inputArray);
-        String[] expectedOutput = {"a", "b", "c", "d", "h", "k", "s"};
-        assertArrayEquals(outputArray, expectedOutput);
-    }
+        // String Input
+        String[] strings = {"c", "a", "e", "b", "d"};
 
-    @Test
-    public void stalinSortDuplicateStringArray() {
-        String[] inputArray = {"s", "b", "d", "a", "d", "c", "h", "b"};
-        String[] outputArray = stalinSort.sort(inputArray);
-        String[] expectedOutput = {"a", "b", "b", "c", "d", "d", "h", "s"};
-        assertArrayEquals(outputArray, expectedOutput);
+        SortUtils.print(stalinSort.sort(strings));
     }
 }