Final answer:
Binary search is not possible under certain circumstances such as when the data is not sorted, when the data structure does not support random access, and when the data size is too small.
Step-by-step explanation:
Binary search is a searching algorithm that is efficient for sorted data. However, there are certain circumstances in which it is not possible to carry out a binary search:
- When the data is not sorted: Binary search requires the data to be in a sorted order. If the data is not sorted, you will not be able to use binary search.
- When the data structure does not support random access: Binary search requires random access to elements, which is not possible in certain data structures like linked lists. In such cases, binary search cannot be performed.
- When the data size is too small: If the data set is very small, it may not be worth the effort to implement binary search. In such cases, simpler linear search algorithms can be used.