Concept:
Binary search is an efficient divide-and-conquer algorithm used to locate a specific target value within a sorted collection.
It operates with a logarithmic time complexity of \(O(\log n)\) by repeatedly comparing the target to the middle element and halving the search space.
Step 1: Analyzing Individual Applications:
(A) Telephone Directory:
A physical or electronic telephone directory is organized alphabetically (sorted order).
Searching for a name is efficiently accomplished using the divide-and-conquer principles of binary search.
(B) Finding an element with minimum or maximum value in a sorted list:
In specialized sorted arrangements, such as rotated sorted arrays or unimodal sequences, modified binary search is standardly applied to find extremes in \(O(\log n)\) time.
(D) Indexing in database:
Database systems organize index blocks (such as B-trees and B+ trees) in sorted order, applying binary search internally to rapidly traverse index nodes and fetch records.
(C) Implementing routing tables:
Network routing tables generally employ longest-prefix matching algorithms implemented via Trie data structures, hash tables, or specialized hardware like TCAM (Ternary Content-Addressable Memory), rather than basic binary search.
Step 2: Conclusion:
Statements (A), (B), and (D) directly represent recognized practical applications of binary search.
Final Answer:
Therefore, the correct choice is (A), which corresponds to (A), (B), and (D) only.