Day 814 Problem

devstromo · devstromo · commit cea30b4ee5f0 · 2024-06-29T22:23:33.000-03:00
diff --git a/daily-coding-problem/src/main/java/com/devstromo/day814/Problem.java b/daily-coding-problem/src/main/java/com/devstromo/day814/Problem.java
@@ -5,18 +5,17 @@
 public class Problem {
 
     public long sumTwoLinkedList(LinkedList<Integer> list1, LinkedList<Integer> list2) {
-        var first = 0L;
-        var second = 0L;
-        var pos = 0;
-        final var n = list1.size();
-        final var m = list2.size();
-
-        for (pos = 0; pos < n; pos++) {
-            first += list1.get(pos) * pow(pos);
+        if (list1 == null && list2 == null) {
+            return 0;
+        }
+        if (list2 == null) {
+            return listNumberRepresentation(list1, list1.size());
         }
-        for (pos = 0; pos < m; pos++) {
-            second += list2.get(pos) * pow(pos);
+        if (list1 == null) {
+            return listNumberRepresentation(list2, list2.size());
         }
+        var first = listNumberRepresentation(list1, list1.size());
+        var second = listNumberRepresentation(list2, list2.size());
         return first + second;
     }
 
@@ -32,4 +31,12 @@ private long pow(long exp) {
         }
         return result;
     }
+
+    private long listNumberRepresentation(LinkedList<Integer> list, int size) {
+        var result = 0L;
+        for (int pos = 0; pos < size; pos++) {
+            result += list.get(pos) * pow(pos);
+        }
+        return result;
+    }
 }
diff --git a/daily-coding-problem/src/test/java/com/devstromo/day814/ProblemUnitTest.java b/daily-coding-problem/src/test/java/com/devstromo/day814/ProblemUnitTest.java
@@ -20,4 +20,20 @@ public void testSumTwoLinkedList() {
         assertEquals(124, problem.sumTwoLinkedList(list1, list2));
     }
 
+    @Test
+    public void testSumTwoLinkedListWithList2Null() {
+        final var list1 = new LinkedList<Integer>();
+        list1.add(9);
+        list1.add(9);
+        assertEquals(99, problem.sumTwoLinkedList(list1, null));
+    }
+
+    @Test
+    public void testSumTwoLinkedListWithList1Null() {
+        final var list2 = new LinkedList<Integer>();
+        list2.add(5);
+        list2.add(2);
+        assertEquals(25, problem.sumTwoLinkedList(null, list2));
+    }
+
 }
