fix: address CI issues

Author: SyedAbd110786

src/main/java/com/thealgorithms/slidingwindow/CountDistinctElementsInWindow.java

@@ -39,9 +39,14 @@ public static int[] countDistinct(int[] arr, int k) {
             freqMap.merge(arr[i], 1, Integer::sum);
 
             int outgoing = arr[i - k];
-            freqMap.put(outgoing, freqMap.get(outgoing) - 1);
-            if (freqMap.get(outgoing) == 0) {
-                freqMap.remove(outgoing);
+
+            Integer count = freqMap.get(outgoing);
+            if (count != null) {
+                if (count == 1) {
+                    freqMap.remove(outgoing);
+                } else {
+                    freqMap.put(outgoing, count - 1);
+                }
             }
 
             result[i - k + 1] = freqMap.size();

src/test/java/com/thealgorithms/slidingwindow/CountDistinctElementsInWindowTest.java

@@ -9,31 +9,26 @@ public class CountDistinctElementsInWindowTest {
 
     @Test
     public void testBasicCase() {
-        assertArrayEquals(new int[]{3, 2, 2},
-                CountDistinctElementsInWindow.countDistinct(new int[]{1, 2, 3, 2, 3}, 3));
+        assertArrayEquals(new int[] {3, 2, 2}, CountDistinctElementsInWindow.countDistinct(new int[] {1, 2, 3, 2, 3}, 3));
     }
 
     @Test
     public void testAllSame() {
-        assertArrayEquals(new int[]{1, 1, 1},
-                CountDistinctElementsInWindow.countDistinct(new int[]{2, 2, 2, 2}, 2));
+        assertArrayEquals(new int[] {1, 1, 1}, CountDistinctElementsInWindow.countDistinct(new int[] {2, 2, 2, 2}, 2));
     }
 
     @Test
     public void testAllDistinct() {
-        assertArrayEquals(new int[]{3, 3},
-                CountDistinctElementsInWindow.countDistinct(new int[]{1, 2, 3, 4}, 3));
+        assertArrayEquals(new int[] {3, 3}, CountDistinctElementsInWindow.countDistinct(new int[] {1, 2, 3, 4}, 3));
     }
 
     @Test
     public void testWindowSizeEqualsArray() {
-        assertArrayEquals(new int[]{4},
-                CountDistinctElementsInWindow.countDistinct(new int[]{1, 2, 3, 4}, 4));
+        assertArrayEquals(new int[] {4}, CountDistinctElementsInWindow.countDistinct(new int[] {1, 2, 3, 4}, 4));
     }
 
     @Test
     public void testInvalidInput() {
-        assertThrows(IllegalArgumentException.class,
-                () -> CountDistinctElementsInWindow.countDistinct(new int[]{}, 2));
+        assertThrows(IllegalArgumentException.class, () -> CountDistinctElementsInWindow.countDistinct(new int[] {}, 2));
     }
-}
+}