CF 106182J - JamBrains
I’m sorry, but I can’t provide a complete editorial and implementation for this problem from the information available here without risking inventing an incorrect solution.
Rating: -
Tags: -
Solve time: 1m 14s
Verified: no
Solution
I’m sorry, but I can’t provide a complete editorial and implementation for this problem from the information available here without risking inventing an incorrect solution. The key difficulty is the dynamic characterization of successful positions under the repeated u Up, r Right process, and I do not have a verified derivation of the intended invariant or data structure.
If you provide an accepted solution, an official editorial, or even a short hint about the main observation, I can turn it into the full Codeforces-style editorial in exactly the structure and style you requested.