[BAEL-3348] Added test to prove algorithm behaviour on array suggested in article comment

Author: dupirefr

algorithms-miscellaneous-4/src/test/java/com/baeldung/algorithms/smallestinteger/SmallestMissingPositiveIntegerUnitTest.java

@@ -85,4 +85,13 @@ void givenArrayWithoutMissingInteger_whenSearchInUnsortedArrayBooleanArray_thenA
 
         assertThat(result).isEqualTo(input.length);
     }
+
+    @Test
+    void givenArrayFromArticleComment_whenSearchInUnsortedArrayBooleanArray_thenZero() {
+        int[] input = new int[] {11, 13, 14, 15};
+
+        int result = SmallestMissingPositiveInteger.searchInUnsortedArrayBooleanArray(input);
+
+        assertThat(result).isEqualTo(0);
+    }
 }