[mandeepj]

> the most difficult math book in history

It is not a math book rather more of a puzzle book. On a side note - it's full of mistakes (your experience may vary though)

If you like to see difficult math then please try to apply for a self-driving car engineer's job.

[andbberger]

whoosh

Pretty sure the prize for 'most difficult math book in history' goes to Dummit and Foote's ponderous tome, Abstract Algebra.

[aje403]

If you are suggesting deep learning involves difficult math then I have just had a stroke

Besides, cracking the code interview is definitely the hardest. Just check out the amazon reviews