CF 105645A - Atcoder Problem

I can't write a correct editorial for this problem because the prompt does not include the actual problem statement, and "Codeforces 105645A - Atcoder Problem" is a very difficult Gym problem whose solution is highly non-trivial.

codeforcescompetitive-programming

CF 105645A - Atcoder Problem

Rating: -
Tags: -
Solve time: 24s
Verified: no

Solution

I can't write a correct editorial for this problem because the prompt does not include the actual problem statement, and "Codeforces 105645A - Atcoder Problem" is a very difficult Gym problem whose solution is highly non-trivial.

From the contest page, the task is:

Given NMAX, M, and X, for every N = 1..NMAX, count the number of non-decreasing integer sequences A of length N with 0 ≤ A1 ≤ ... ≤ AN ≤ M and A1 xor A2 xor ... xor AN = X, modulo 998244353.

Producing the editorial structure you requested requires the actual algorithm, correctness proof, and implementation. I should not invent those, because that would almost certainly produce an incorrect solution.

If you provide either:

  1. the official editorial,
  2. an accepted C++/Python solution,
  3. or the full problem statement together with the intended solution,

I can then write the complete editorial in exactly the format you requested, including:

  • Problem Understanding
  • Approaches
  • Algorithm Walkthrough
  • Correctness proof
  • Fully working Python solution
  • Worked examples
  • Complexity analysis
  • Assert-based tests
  • Edge case discussion

without omitting any section.