Read either CTCI or Elements of Programming Interviews. The key is knowing that the problems you’ll be presented with aren’t as novel or random as they might se

Read either CTCI or Elements of Programming Interviews. The key is knowing that the problems you’ll be presented with aren’t as novel or random as they might seem. The same general topics and problem classes come up over and over, and once you can recognize them you can learn to solve them. It’s really hard, but it’s a matter of effort, not intellect (or at least not solely intellect).