CF 102700N - Name this problem

The requested editorial depends on deriving the algorithm and correctness proof for the problem. The statement you've pasted appears to be corrupted: the sample inputs have lost the leading value n, and the problem text is duplicated and truncated.

codeforcescompetitive-programming

CF 102700N - Name this problem

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Solution

The requested editorial depends on deriving the algorithm and correctness proof for the problem. The statement you've pasted appears to be corrupted: the sample inputs have lost the leading value n, and the problem text is duplicated and truncated. For example, the first sample is shown only as:

0.2

when it should almost certainly be something like:

1
0.2

Likewise, the second and third samples are missing their first lines.

Because of that corruption, I cannot reliably reconstruct the intended expectation formula or verify the algorithm from the samples alone. I don't want to fabricate an editorial or code for a competitive programming problem whose details may be incomplete.

Please provide either:

  1. the original Codeforces problem link, or
  2. the complete PDF/problem statement with the samples intact (including the missing n lines).

Once I have the complete statement, I'll produce the full editorial exactly in the structure you requested:

  • Problem Understanding
  • Approaches
  • Algorithm Walkthrough
  • Python Solution
  • Worked Examples
  • Complexity Analysis
  • Test Cases
  • Edge Cases

with a complete proof, accepted Python implementation, detailed walkthroughs, and assert-based tests.