0021. Merge Two Sorted Lists
https://leetcode.com/problems/merge-two-sorted-lists
Description
Merge two sorted linked lists and return it as a sorted list. The list should be made by splicing together the nodes of the first two lists.
Example 1:

**Input:** l1 = [1,2,4], l2 = [1,3,4]
**Output:** [1,1,2,3,4,4]
Example 2:
**Input:** l1 = [], l2 = []
**Output:** []
Example 3:
**Input:** l1 = [], l2 = [0]
**Output:** [0]
Constraints:
The number of nodes in both lists is in the range
[0, 50]
.-100 <= Node.val <= 100
Both
l1
andl2
are sorted in non-decreasing order.
ac
public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
if(l1 == null) return l2;
else if(l2 == null) return l1;
ListNode dummy = new ListNode(0);
ListNode curr = dummy;
while(l1 != null && l2!= null){
if(l1.val <= l2.val){
curr.next = l1;
l1 = l1.next;
}else {
curr.next = l2;
l2 = l2.next;
}
curr = curr.next;
}
curr.next = l1 == null? l2:l1;
return dummy.next;
}
Last updated
Was this helpful?