Check if array is sorted

Author: kshitizsaini113

src/main/java/array/check_if_array_is_sorted/CheckSorted.java

@@ -0,0 +1,33 @@
+package array.check_if_array_is_sorted;
+
+/**
+ * Utility class that provides a method to check
+ * whether an integer array is sorted in non-decreasing (ascending) order.
+ */
+public class CheckSorted {
+
+    /**
+     * Checks whether the given array is sorted in ascending order.
+     *
+     * <p>An array is considered sorted if:
+     * <ul>
+     *   <li>It is {@code null}</li>
+     *   <li>It has zero or one element</li>
+     *   <li>Every element is less than or equal to the next element</li>
+     * </ul>
+     *
+     * @param nums the array of integers to check
+     * @return {@code true} if the array is sorted or null; {@code false} otherwise
+     */
+    public boolean checkSorted(int[] nums) {
+        if (nums == null || nums.length <= 1) {
+            return true;
+        }
+        for (int i = 0; i < nums.length - 1; i++) {
+            if (nums[i] > nums[i + 1]) {
+                return false;
+            }
+        }
+        return true;
+    }
+}

src/main/java/array/check_if_array_is_sorted/package-info.java

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+/**
+ * Provides utilities for performing checks on arrays.
+ *
+ * <p>This package currently includes functionality to determine
+ * whether an integer array is sorted in ascending order.
+ */
+package array.check_if_array_is_sorted;

src/test/java/array/check_if_array_is_sorted/CheckSortedTest.java

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+package array.check_if_array_is_sorted;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class CheckSortedTest {
+
+    private final CheckSorted checker = new CheckSorted();
+
+    @Test
+    void testNullArray() {
+        assertTrue(checker.checkSorted(null));
+    }
+
+    @Test
+    void testEmptyArray() {
+        assertTrue(checker.checkSorted(new int[]{}));
+    }
+
+    @Test
+    void testSingleElementArray() {
+        assertTrue(checker.checkSorted(new int[]{5}));
+    }
+
+    @Test
+    void testAlreadySortedArray() {
+        assertTrue(checker.checkSorted(new int[]{1, 2, 3, 4, 5}));
+    }
+
+    @Test
+    void testArrayWithDuplicates() {
+        assertTrue(checker.checkSorted(new int[]{1, 2, 2, 3, 3}));
+    }
+
+    @Test
+    void testUnsortedArray() {
+        assertFalse(checker.checkSorted(new int[]{3, 1, 4, 2}));
+    }
+
+    @Test
+    void testDescendingArray() {
+        assertFalse(checker.checkSorted(new int[]{5, 4, 3, 2, 1}));
+    }
+}