I've seen some very bad interviewers that will fault you for non-perfect solutions, but most will have some sort of reasonable leeway in what they will take as a solution.
Some people I know who are URT would not even have to solve the problem to get a passing grade. Some know this and actively take advantage of it (and good for them) but others are blissfully unaware and are shocked when they find out that what they experience isn't the norm.