Efficient algorithm for finding the breaking point between two entries

Question

I've got an API endpoint which looks like this: http://foo.bar/rest-method/{identifier}.
This API returns an object that looks like that:

{
 name: "Example",
 version: "1.0.5.3937"
}

Now I know that the entry with the identifier 2923711253 has got version 1.0.5.3937 while the entry with the identifier 2923823024 has 1.0.6.1334.

I want to find out which identifier is the last one using version 1.0.5.3937 and which is the first one using 1.0.6.1334. I call it 'the breaking point'.

Of course I could write a loop which simply checks all the identifiers which are between the two definied one's, but that seems very inefficient to me.

What algorithm should be used here?

Answer 1

If it is guaranteed that higher identifier means not lesser version then the fastest way is binary search.

• jk.: indeed, git or hg bisect