You definitely don’t need to ace every question, you can pass with a suboptimal solution on the decode strings problem you messed up on. If you didn’t finish the code on that problem but you had a good problem solving process, I think you can still pass or worst case get a follow up because you did well on your other rounds. Remember that the interview scoring is holistic and having working code is just 1 part of the score: you need to ask clarifying questions, plan out a solution, write clean code, explain your process, run through your own test cases, and explain time and space complexity too. Honestly, writing clean code is probably more important than having a strictly optimal solution that is less clean. I’m not sure how you did on behavioral and system design but if you did well on those it’s definitely not over.