i went through Facebook top 50 questions. Some of them are hard but when i saw top 50 Google questions, i was able to come up with optimal solution for less than half of the problems. Some problems took me a while to even understand the top voted solutions.

i feel really dumb and feel down. Even if i practice 500 more questions i doubt i can reach optimal solution in interview for some of these Fang questions. So its hopeless for me to go to Fang?