Add tests, remove main in RangeInSortedArray

DIRECTORY.md

@@ -1018,6 +1018,7 @@
             * [MedianOfRunningArrayTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/misc/MedianOfRunningArrayTest.java)
             * [MirrorOfMatrixTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/misc/MirrorOfMatrixTest.java)
             * [PalindromeSinglyLinkedListTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/misc/PalindromeSinglyLinkedListTest.java)
+            * [RangeInSortedArrayTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/misc/RangeInSortedArrayTest.java)
             * [TwoSumProblemTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/misc/TwoSumProblemTest.java)
           * others
             * [ArrayLeftRotationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/ArrayLeftRotationTest.java)

src/main/java/com/thealgorithms/misc/RangeInSortedArray.java

@@ -1,18 +1,9 @@
 package com.thealgorithms.misc;
 
-import java.util.Arrays;
-
 public final class RangeInSortedArray {
     private RangeInSortedArray() {
     }
 
-    public static void main(String[] args) {
-        // Testcases
-        assert Arrays.equals(sortedRange(new int[] {1, 2, 3, 3, 3, 4, 5}, 3), new int[] {2, 4});
-        assert Arrays.equals(sortedRange(new int[] {1, 2, 3, 3, 3, 4, 5}, 4), new int[] {5, 5});
-        assert Arrays.equals(sortedRange(new int[] {0, 1, 2}, 3), new int[] {-1, -1});
-    }
-
     // Get the 1st and last occurrence index of a number 'key' in a non-decreasing array 'nums'
     // Gives [-1, -1] in case element doesn't exist in array
     public static int[] sortedRange(int[] nums, int key) {

src/test/java/com/thealgorithms/misc/RangeInSortedArrayTest.java

@@ -0,0 +1,35 @@
+package com.thealgorithms.misc;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.stream.Stream;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+public class RangeInSortedArrayTest {
+
+    @ParameterizedTest(name = "Test case {index}: {3}")
+    @MethodSource("provideSortedRangeTestCases")
+    void testSortedRange(int[] nums, int key, int[] expectedRange, String description) {
+        assertArrayEquals(expectedRange, RangeInSortedArray.sortedRange(nums, key), description);
+    }
+
+    private static Stream<Arguments> provideSortedRangeTestCases() {
+        return Stream.of(Arguments.of(new int[] {1, 2, 3, 3, 3, 4, 5}, 3, new int[] {2, 4}, "Range for key 3 with multiple occurrences"), Arguments.of(new int[] {1, 2, 3, 3, 3, 4, 5}, 4, new int[] {5, 5}, "Range for key 4 with single occurrence"),
+            Arguments.of(new int[] {0, 1, 2}, 3, new int[] {-1, -1}, "Range for non-existent key"), Arguments.of(new int[] {}, 1, new int[] {-1, -1}, "Range in empty array"), Arguments.of(new int[] {1, 1, 1, 2, 3, 4, 5, 5, 5}, 1, new int[] {0, 2}, "Range for key at start"),
+            Arguments.of(new int[] {1, 1, 1, 2, 3, 4, 5, 5, 5}, 5, new int[] {6, 8}, "Range for key at end"));
+    }
+
+    @ParameterizedTest(name = "Test case {index}: {3}")
+    @MethodSource("provideGetCountLessThanTestCases")
+    void testGetCountLessThan(int[] nums, int key, int expectedCount, String description) {
+        assertEquals(expectedCount, RangeInSortedArray.getCountLessThan(nums, key), description);
+    }
+
+    private static Stream<Arguments> provideGetCountLessThanTestCases() {
+        return Stream.of(Arguments.of(new int[] {1, 2, 3, 3, 4, 5}, 3, 4, "Count of elements less than existing key"), Arguments.of(new int[] {1, 2, 3, 3, 4, 5}, 4, 5, "Count of elements less than non-existing key"), Arguments.of(new int[] {1, 2, 2, 3}, 5, 4, "Count with all smaller elements"),
+            Arguments.of(new int[] {2, 3, 4, 5}, 1, 0, "Count with no smaller elements"), Arguments.of(new int[] {}, 1, 0, "Count in empty array"));
+    }
+}