Description
You are given the heads of two sorted linked lists list1 and list2. Merge the two lists into 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.
Examples
Input:
list1 = [1,2,4], list2 = [1,3,4]Output:
[1,1,2,3,4,4]Explanation:
Comparing heads at each step: 1=1 (take either), 1<2 (take 1), 2<3 (take 2), 3<4 (take 3), 4=4 (take either), append remaining 4.
Input:
list1 = [], list2 = []Output:
[]Explanation:
Both input lists have no nodes (null heads). Merging two empty lists results in an empty list with no elements.
Input:
list1 = [], list2 = [0]Output:
[0]Explanation:
One list is empty, so the merged result is simply the other list: [0].
Constraints
- •
The number of nodes in both lists is in the range [0, 50] - •
-100 ≤ Node.val ≤ 100 - •
Both list1 and list2 are sorted in non-decreasing order.