All three problems use the same core algorithm:
| Problem | Question | Answer |
|---|---|---|
| Activity Selection | Max non-overlapping? | Count selected |
| Non-overlapping Intervals | Min to remove? | - count |
| Minimum Arrows | Min arrows? | Number of groups |
The underlying technique is identical: sort by end time, greedily select non-overlapping. The answer is derived differently but This algorithm is the same. Recognize the pattern, not just the story.