Merge Two Sorted Lists
Description
You are given the heads of two sorted linked lists list1
and list2
.
Merge the two lists in a one sorted list. The list should be made by splicing together the nodes of the first two lists.
Return the head of the merged linked list.
Example 1:
![](https://assets.leetcode.com/uploads/2020/10/03/merge_ex1.jpg)
Input: list1 = [1,2,4], list2 = [1,3,4] Output: [1,1,2,3,4,4]
Example 2:
Input: list1 = [], list2 = [] Output: []
Example 3:
Input: list1 = [], list2 = [0] Output: [0]
Constraints:
- The number of nodes in both lists is in the range
[0, 50]
. -100 <= Node.val <= 100
- Both
list1
andlist2
are sorted in non-decreasing order.
Solution(javascript)
/**
* Definition for singly-linked list.
* function ListNode(val, next) {
* this.val = (val===undefined ? 0 : val)
* this.next = (next===undefined ? null : next)
* }
*/
/**
* @param {ListNode} list1
* @param {ListNode} list2
* @return {ListNode}
*/
var mergeTwoLists = function(list1, list2) {
let outputList = new ListNode();
let selectedNode = outputList;
let tempNode;
while (true) {
if (list1 && list2 && list1.val <= list2.val || list1 && list2 == undefined) {
selectedNode.next = list1;
list1 = list1.next;
} else if (list1 && list2 || list2 && list1 == undefined) {
selectedNode.next = list2;
list2 = list2.next;
} else {
break;
}
selectedNode = selectedNode.next;
}
return outputList.next;
};