Back

Merge Two Sorted Lists

easy

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.

Test Cases

Copy an input into the main harness and Run to verify
Input
list1 = [1,2,4], list2 = [1,3,4]
Expected Output
[1,1,2,3,4,4]
Input
list1 = [], list2 = []
Expected Output
[]
Input
list1 = [], list2 = [0]
Expected Output
[0]

Constraints

  • The number of nodes in both lists is in the range [0, 50].
  • -100 <= Node.val <= 100
  • Both lists are sorted in non-decreasing order.

Hints

Hint 1 — click to reveal

Use a dummy head so you never special-case the first node.

Hint 2 — click to reveal

Always attach the smaller current node, then advance that list.

Java Compiler

Powered by OneCompiler. Starter code loads automatically — edit and hit Run.