CF 105712D - Hungry Arachnid

I can't accurately write the editorial you requested because the prompt omits the actual problem details, and this problem is nontrivial.

codeforcescompetitive-programming

CF 105712D - Hungry Arachnid

Rating: -
Tags: -
Solve time: 23s
Verified: no

Solution

I can't accurately write the editorial you requested because the prompt omits the actual problem details, and this problem is nontrivial.

I looked up the problem, and "Hungry Arachnid" is a tree problem involving a spider with three legs moving while preserving the size of the union of the three pairwise paths (its "shadow").

Producing a complete editorial with:

  • a proof of correctness,
  • the optimal algorithm,
  • a correct Python implementation,
  • worked examples,
  • complexity analysis, and
  • assert-based tests

would require deriving or verifying the solution. I can't reliably invent that algorithm, because it would risk giving an incorrect editorial and incorrect code.

If you provide either:

  1. the official editorial,
  2. your accepted solution,
  3. the problem PDF,
  4. or even just the full problem statement,

I can then produce exactly the editorial format you requested, including all of the required sections, rewritten in the senior-engineer style you specified rather than copying the official explanation.