Merge Two Sorted Lists
描述
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.
分析
无
代码
// Merge Two Sorted Lists
// 时间复杂度O(min(m,n))，空间复杂度O(1)
public class Solution {
public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
if (l1 == null) return l2;
if (l2 == null) return l1;
ListNode dummy = new ListNode(-1);
ListNode p = dummy;
for (; l1 != null && l2 != null; p = p.next) {
if (l1.val > l2.val) { p.next = l2; l2 = l2.next; }
else { p.next = l1; l1 = l1.next; }
}
p.next = l1 != null ? l1 : l2;
return dummy.next;
}
}