Here is a comparison table:
| Problem Type | Sort By | Goal |
|---|---|---|
| Activity Selection | End | Max non-overlapping |
| Merge Intervals | Start | Combine overlapping |
| Insert Interval | Already sorted | Add and merge |
| Intersections | Two pointers | Find overlaps |
| Remove Covered | Start (end desc) | Count non-covered |
| Minimum Cover | Start | Cover range with fewest |
Recognize the type, apply the pattern. Each problem type has a signature sorting strategy.