When would you use a binary search?

A binary search is an efficient algorithm used to find a specific element in a sorted dataset. It operates by dividing the dataset in half with each step, allowing it to eliminate large portions of data from consideration after each comparison. This drastically reduces the number of comparisons needed to find an element compared to a linear search, which would check each element one by one.

Using a binary search is effective because it leverages the property of a sorted dataset, enabling it to quickly narrow down the search interval. Such efficiency makes it particularly valuable when dealing with large amounts of data where reduction of comparisons can significantly enhance performance.

In contrast, utilizing a binary search with an unsorted dataset would be ineffective, as the necessary order for making logical decisions about which half of the dataset to search next does not exist. Searching in a text file may rely more on linear search techniques unless specific indexed structures are in place. Lastly, complex data structures could introduce additional overhead and complexity that might necessitate other searching methodologies tailored to their unique features rather than the straightforward binary search.