Why should you care?

Some problems need local choices; others need search trees.

See it live — copy this example

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

// Activity Selection
// Greedy: sort + pick
// Backtracking: choose/explore/unchoose

What happened?

• Prove greedy stays safe, or bound the backtracking tree.
• Follow the steps below — typing the code yourself is the fastest way to learn.

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 Activity Selection. You know the complexity class. You tested at least one edge case.

Activity Selection drill

AlgoVerse interview prompt on activity selection.

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