I think it depends as LC hards can be hard for multiple reasons. I feel like, most of the time, they're hard because there are difficult edge cases to account for.Take problems like Alien Dictionary or Word Search II. Even when you understand the problem and what the ideal solution is, it can be tricky to code as accounting for edge cases is non-trivial.In other cases, the problem could have multiple solutions, but to get the most optimal, it may require knowing a "math trick" or a lot of practice to recognize the pattern and the different approaches you could use.There are many problems that initially look like knapsack problems and can be solved using a DP approach, but that's actually the slower approach and you could solve it faster with a priority queue or something like that. Course Schedule III i think is an example of this.But in the case of an interview, it can be "good enough" to know one solution even if it isn't the most optimal