Interview Questions

DP solves problems by breaking them into overlapping subproblems and storing results (memoization or tabulation) to avoid recomputation. Use it when a problem has optimal substructure and overlapping subproblems — e.g. knapsack, edit distance, longest common subsequence.

Event delegation attaches a single listener to a common ancestor instead of many listeners on individual children. Events bubble up, and you inspect `event.target` to act on the originating element. It reduces memory use and works for dynamically-added elements.

In a distributed system you can guarantee at most two of Consistency, Availability, and Partition tolerance. Since network partitions are unavoidable, you effectively choose between consistency (CP) and availability (AP) during a partition.