Your question is Sliding Window Job Scheduling. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Tell me about how you would solve a problem that uses the sliding window technique where you can flip 0s to 1s, and you must also respect job dependencies where b[i] must be completed before a[i] can start.