[week2] solve 21. Merge Two Sorted Lists

Author: bky373

merge-two-sorted-lists/bky373.java

@@ -0,0 +1,33 @@
+/**
+ * TC: O(N)
+ * SC: O(N)
+ */
+class Solution_21 {
+    public ListNode mergeTwoLists(ListNode list1, ListNode list2) {
+        if (list1 == null && list2 == null) {
+            return null;
+        }
+
+        List<Integer> nums = new ArrayList<>();
+
+        while (list1 != null) {
+            nums.add(list1.val);
+            list1 = list1.next;
+        }
+        while (list2 != null) {
+            nums.add(list2.val);
+            list2 = list2.next;
+        }
+
+        Object[] arr = nums.toArray();
+        Arrays.sort(arr);
+
+        ListNode head = new ListNode((int) arr[0]);
+        ListNode curr = head;
+        for (int i=1; i<arr.length; i++) {
+            curr.next = new ListNode((int) arr[i]);
+            curr = curr.next;
+        }
+        return head;
+    }
+}