alan1914

``` # java public int[] twoSum(int[] nums, int target) { int length = nums.length; HashMap map = new HashMap(); for (int i = 0; i < length; i++) { int...

```java // java -> 递归 public ListNode mergeTwoLists(ListNode list1, ListNode list2) { if (null == list1) { return list2; } if (null == list2) { return list1; } if (list1.val