Leetcode 2483. Minimum Penalty for a Shop

Given a string of 'Y'/'N' arrivals, choose an index j (0..n) to close the shop so that open hours with 'N' and closed hours with 'Y' incur the fewest penalties; return the earliest j minimizing that score. This reduces to finding the split that minimizes mismatches and can be found with a single pass using prefix/suffix counts.