Why should you care?

Lists train null checks and in-place rewiring.

See it live — copy this example

Run snippets in a .NET console app, LINQPad, or https://dotnetfiddle.net. Write Big O above every solution.

public class ListNode {
  public int Val; public ListNode Next;
  public ListNode(int v, ListNode next = null) { Val = v; Next = next; }
}
// Merge Two Sorted Lists

What happened?

• Draw nodes before coding.
• Always handle empty/single-node cases.

Practice next

1. Type the snippet in a C# console or LINQPad.
2. Write Big O on top of your solution.
3. Test empty / single-element edge cases.
4. Add a failing test then fix it.
5. Rename variables to domain words.

Remember

You can code a small C# example for Merge Two Sorted Lists. You know the complexity class. You tested at least one edge case.

Merge Two Sorted Lists drill

AlgoVerse interview prompt on merge two sorted lists.

Outcome: You recognize the pattern and ship a correct C# sketch.