Add tests, remove main in RangeInSortedArray

DIRECTORY.md

@@ -995,6 +995,7 @@
             * [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 +1,70 @@
+package com.thealgorithms.misc;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class RangeInSortedArrayTest {
+
+    @Test
+    public void testSortedRangeWithMultipleOccurrences() {
+        int[] nums = {1, 2, 3, 3, 3, 4, 5};
+        assertArrayEquals(new int[] {2, 4}, RangeInSortedArray.sortedRange(nums, 3), "Range for key 3 should be [2, 4]");
+    }
+
+    @Test
+    public void testSortedRangeWithSingleOccurrence() {
+        int[] nums = {1, 2, 3, 3, 3, 4, 5};
+        assertArrayEquals(new int[] {5, 5}, RangeInSortedArray.sortedRange(nums, 4), "Range for key 4 should be [5, 5]");
+    }
+
+    @Test
+    public void testSortedRangeWithNoOccurrences() {
+        int[] nums = {0, 1, 2};
+        assertArrayEquals(new int[] {-1, -1}, RangeInSortedArray.sortedRange(nums, 3), "Range for key 3 should be [-1, -1] since it doesn't exist");
+    }
+
+    @Test
+    public void testSortedRangeInEmptyArray() {
+        int[] nums = {};
+        assertArrayEquals(new int[] {-1, -1}, RangeInSortedArray.sortedRange(nums, 1), "Range for any key in an empty array should be [-1, -1]");
+    }
+
+    @Test
+    public void testSortedRangeAtStartAndEnd() {
+        int[] nums = {1, 1, 1, 2, 3, 4, 5, 5, 5};
+        assertArrayEquals(new int[] {0, 2}, RangeInSortedArray.sortedRange(nums, 1), "Range for key 1 should be [0, 2]");
+        assertArrayEquals(new int[] {6, 8}, RangeInSortedArray.sortedRange(nums, 5), "Range for key 5 should be [6, 8]");
+    }
+
+    @Test
+    public void testGetCountLessThanWithExistingKey() {
+        int[] nums = {1, 2, 3, 3, 4, 5};
+        assertEquals(4, RangeInSortedArray.getCountLessThan(nums, 3), "Count of elements less than 3 should be 2");
+    }
+
+    @Test
+    public void testGetCountLessThanWithNonExistingKey() {
+        int[] nums = {1, 2, 3, 3, 4, 5};
+        assertEquals(5, RangeInSortedArray.getCountLessThan(nums, 4), "Count of elements less than 4 should be 5");
+    }
+
+    @Test
+    public void testGetCountLessThanWithAllSmallerElements() {
+        int[] nums = {1, 2, 2, 3};
+        assertEquals(4, RangeInSortedArray.getCountLessThan(nums, 5), "Count of elements less than 5 should be 4");
+    }
+
+    @Test
+    public void testGetCountLessThanWithNoSmallerElements() {
+        int[] nums = {2, 3, 4, 5};
+        assertEquals(0, RangeInSortedArray.getCountLessThan(nums, 1), "Count of elements less than 1 should be 0");
+    }
+
+    @Test
+    public void testGetCountLessThanWithEmptyArray() {
+        int[] nums = {};
+        assertEquals(0, RangeInSortedArray.getCountLessThan(nums, 1), "Count of elements less than 1 in an empty array should be 0");
+    }
+}