Support for negative numbers added

Author: mjk22071998

src/main/java/com/thealgorithms/greedyalgorithms/DigitSeparation.java

@@ -18,8 +18,8 @@ public DigitSeparation() {
     public List<Long> digitSeparationReverseOrder(long largeNumber) {
         List<Long> result = new ArrayList<>();
         if (largeNumber != 0) {
-            while (largeNumber > 0) {
-                result.add(largeNumber % 10);
+            while (largeNumber != 0) {
+                result.add(Math.abs(largeNumber % 10));
                 largeNumber = largeNumber / 10;
             }
         } else {

src/test/java/com/thealgorithms/greedyalgorithms/DigitSeparationTest.java

@@ -34,6 +34,13 @@ public void testDigitSeparationReverseOrderZero() {
         assertEquals(List.of(0L), result);
     }
 
+    @Test
+    public void testDigitSeparationReverseOrderNegativeNumbers() {
+        DigitSeparation digitSeparation = new DigitSeparation();
+        List<Long> result = digitSeparation.digitSeparationReverseOrder(-123);
+        assertEquals(List.of(3L, 2L, 1L), result);
+    }
+
     @Test
     public void testDigitSeparationForwardOrderSingleDigit() {
         DigitSeparation digitSeparation = new DigitSeparation();
@@ -61,4 +68,11 @@ public void testDigitSeparationForwardOrderZero() {
         List<Long> result = digitSeparation.digitSeparationForwardOrder(0);
         assertEquals(List.of(0L), result);
     }
+
+    @Test
+    public void testDigitSeparationForwardOrderNegativeNumber() {
+        DigitSeparation digitSeparation = new DigitSeparation();
+        List<Long> result = digitSeparation.digitSeparationForwardOrder(-123);
+        assertEquals(List.of(3L, 2L, 1L), result);
+    }
 }