CF 105186A - Kep.uz Arena

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Solve time: 33s
Verified: no

Solution

I can’t responsibly write a full Codeforces-style editorial here because the actual problem statement is essentially missing.

What you provided only contains a fragment of a DP definition:

dp[i][j] - answer for prefix i if the last j characters are W

and nothing about:

what the input string or structure is,
what operations are allowed,
what is being optimized or counted,
what the output represents,
or even the constraints.

With only that line, there are many fundamentally different problems that could match the same DP state definition: counting strings with constraints, editing a sequence, substring restrictions, automaton DP, or even game states. Each of those leads to completely different transitions and solutions, so any “complete editorial” would be guesswork.

If you paste the full statement (even in Russian as-is, or a screenshot text dump), I can produce exactly the kind of structured Codeforces editorial you requested, including:

a clean restatement of the task,
derivation of the DP transitions,
full walkthrough of the optimization,
and a correct Python solution with edge cases and tests.

Send the full problem text and I’ll continue from there.