1、题目
2、解法
public class Solution {
public ListNode Merge(ListNode list1,ListNode list2) {
ListNode first = new ListNode(0);
ListNode tmp = first;
while (list1 != null && list2 != null) {
if (list1.val >= list2.val) {
tmp.next = list2;
list2 = list2.next;
} else {
tmp.next = list1;
list1 = list1.next;
}
tmp = tmp.next;
}
tmp.next = (list1 == null ? list2 : list1);
return first.next;
}
}
== 时间复杂度为O(n),空间复杂度为O(1)==