Look for these signals in the problem:
- "Sorted array" explicitly mentioned: Classic binary search directly applies. Even if not finding exact values, sorted order enables halving.
- "Find minimum/maximum that satisfies condition": Binary search on the answer space.
If you can verify a candidate answer in , search the range in .
- "Rotated sorted array": Modified binary search handles the rotation by checking which half is properly sorted.
- "Find boundary" or "first/last occurrence": Binary search variants find transition points between valid and invalid regions.