Library Book Search

A librarian maintains a sorted list of book IDs. Your task is to determine the position of a given book ID in the list. If the book ID exists, return its index; if it's not found, return -1. Input format: - The first line contains an integer n (1 <= n <= 10^5), the number of books. - The second line contains n space-separated integers representing book IDs. - The third line contains an integer book_id representing the ID you want to search for. Output format: - Print the index of the book ID if it exists, or -1 if it does not. Example: Input: 4 101 103 104 105 103 Output: 1