Binary Search in Python: Find Fixed Point

In this video, we will be solving the following problem:

Given an array of n distinct integers sorted in ascending order, write a function that returns a "fixed point" in the array. If there is not a
fixed point return "None".

A fixed point in an array "A" is an index "i" such that A[i] is equal to "i".

This video is one part of the Binary Search playlist on my channel. For more videos on binary search and how to apply it to various problems, check out the other videos:

The software written in this video is available at:

Do you like the development environment I'm using in this video? It's a customized version of vim that's enhanced for Python development. If you want to see how I set up my vim, I have a series on this here:

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[ayushidalal]

What will be the approach to solve this ques if duplicates are allowed?

[liveToRadiance]

I never write a comment but I couldn't help myself. I went through enough videos for Algorithm in Python and yours are the best by far. It is so thorough and precise, I repeated each video probably about twice and I can write it out of scratch even three days later. Thank you very much!

[supriyosarkar]

What if there are multiple fixed points?

[samarthbhandari]

We need to also assume that we only have one fixed point in the array right? Because like having duplicates, this method should also not work for multiple fixed points.

[adityagedam]

nothing else just here, to thank you .