Given a sorted array x[] of integers in increasing order of size n, the task is to find two integers x[i] and x[j], such that a point (x[i], x[j]) lies inside a rectangle whose four vertices are mentioned.

Can anyone please share a O(n) algorithm for this? The code is not necessary.

I would grateful.

PS: I tried a lot, but didn't come up with anything linear. Also, I didn't know how to phrase it for Google search.