Leetcode 2286. Booking Concert Tickets in Groups

Support two booking operations on n rows with m seats each: gather(k,maxRow) must find the smallest row ≤ maxRow with k consecutive free seats and return the starting seat, while scatter(k,maxRow) must determine (and if possible allocate) k seats across rows 0..maxRow using the smallest row and seat numbers. The challenge is to maintain per-row free-seat information and support efficient range-max and prefix-sum queries/updates to locate contiguous blocks and verify/perform greedy allocations.