Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.
Solution:
Merge sort 的核心部分。（or Merge two array）
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
public class Solution
{
public ListNode mergeTwoLists(ListNode l1, ListNode l2)
{
ListNode result = new ListNode(0);
ListNode head = result;
while (l1 != null || l2 != null)
{
if (l1 == null)
{
result.next = l2;
l2 = l2.next;
result = result.next;
}
else if (l2 == null)
{
result.next = l1;
l1 = l1.next;
result = result.next;
}
else
{
if (l1.val > l2.val)
{
result.next = l2;
l2 = l2.next;
result = result.next;
} else
{
result.next = l1;
l1 = l1.next;
result = result.next;
}
}
}
return head.next;
}
}
