Refact.ai Match 1 (Codeforces Round 985)

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ContestId
Name
Phase
Frozen
Duration (Seconds)
Relative Time
Start Time
2029 Refact.ai Match 1 (Codeforces Round 985) FINISHED False 10800 45242723 Nov. 9, 2024, 2:35 p.m.

Problems

Solved
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Name
Type
Tags
Community Tag
Rating
( 110 ) H Message Spread PROGRAMMING bitmasks combinatorics dp

Given is an undirected graph with (n) vertices and (m) edges. Each edge connects two vertices ((u, v)) and has a probability of (\frac{p}{q}) of appearing each day. Initially, vertex (1) has a message. At the end of the day, a vertex has a message if and only if itself or at least one of the vertices adjacent to it had the message the day before. Note that each day, each edge chooses its appearance independently. Calculate the expected number of days before all the vertices have the message, modulo (998\,244\,353). The first line contains two integers (n) and (m) ((1\leq n\leq 21), (n-1\leq m\leq\frac{n(n-1)}{2})). Then (m) lines follow, each containing four integers (u), (v), (p), and (q) ((1\leq u\neq v\leq n), (1\leq p<q<998\,244\,353), (\gcd(p,q)=1)) — there is an undirected edge between (u) and (v), and it has a probability of appearance of (\frac{p}{q}) each day. It is guaranteed that there are no self-loops or multiple-edges in the graph and that the graph is connected if all of the edges appear. Additional constraint in the input: Let (g_{i,j}) be the probability of appearance of the edge between (i) and (j) ((g_{i,j}=0) if there is no edge between (i) and (j)). It is guaranteed that for any (S\subseteq\{1,2,\ldots,n\}) ((|S|\ge 1)), () \prod_{i\in S}\left(\prod_{j\in\{1,2,\ldots,n\}\setminus S}(1-g_{i,j})\right)\not\equiv1\pmod{998\,244\,353}. () Print a single integer in the only line of the output — the expected number of days, modulo (998\,244\,353). Formally, let (M = 998\,244\,353). It can be shown that the exact answer can be expressed as an irreducible fraction (\frac{p}{q}), where (p) and (q) are integers and (q \not \equiv 0 \pmod{M}). Output the integer equal to (p \cdot q^{-1} \bmod M). In other words, output such an integer (x) that (0 \le x < M) and $$$x \cdot q \equiv p \pmod{

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Refact.ai Match 1 (Codeforces Round 985) Editorial

Submissions

Submission Id
Author(s)
Index
Submitted
Verdict
Language
Test Set
Tests Passed
Time taken (ms)
Memory Consumed (bytes)
Tags
Rating
290785349 hos.lyric H Nov. 9, 2024, 8:57 p.m. OK C++17 (GCC 7-32) TESTS 69 6061 210944000
290785367 hos.lyric H Nov. 9, 2024, 8:57 p.m. OK C++17 (GCC 7-32) TESTS 69 6156 210944000
290785375 hos.lyric H Nov. 9, 2024, 8:57 p.m. OK C++20 (GCC 13-64) TESTS 69 5953 210636800
290806378 nbhoanh09hanoi H Nov. 10, 2024, 4:55 a.m. OK C++20 (GCC 13-64) TESTS 69 7671 4710400
290771421 StellarSpecter H Nov. 9, 2024, 6:19 p.m. OK C++20 (GCC 13-64) TESTS 69 7781 4710400
290757456 hos.lyric H Nov. 9, 2024, 4:58 p.m. OK C++20 (GCC 13-64) TESTS 69 7936 4710400
290765761 jiangly H Nov. 9, 2024, 5:30 p.m. OK C++23 (GCC 14-64, msys2) TESTS 69 5374 206643200
290787780 Benq H Nov. 9, 2024, 9:41 p.m. OK C++23 (GCC 14-64, msys2) TESTS 69 6203 286720000
290773488 Ion_Gravirei H Nov. 9, 2024, 6:36 p.m. OK C++23 (GCC 14-64, msys2) TESTS 69 7499 4812800
290751120 Benq H Nov. 9, 2024, 4:39 p.m. OK C++23 (GCC 14-64, msys2) TESTS 69 11327 4812800
290781610 rainboy H Nov. 9, 2024, 8:03 p.m. OK C++23 (GCC 14-64, msys2) TESTS 69 11343 596787200

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