Codeforces Round 1095 (Div. 2)

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ContestId
Name
Phase
Frozen
Duration (Seconds)
Relative Time
Start Time
2226 Codeforces Round 1095 (Div. 2) FINISHED False 8100 1178664 April 28, 2026, 2:35 p.m.

Problems

Solved
Index
Name
Type
Tags
Community Tag
Rating
( 193 ) F Inversion Invasion PROGRAMMING math number theory

There is an array (a) of length (n). Initially, (a_i = 0) for all (1 \le i \le n). A permutation(^{\text{∗}}) (p) is said to be valid if at least one of the following conditions is satisfied for every (1 \le i \le n): (a_i = 0). (\gcd(p_i, n) = a_i). You have to process (q) queries. In each query, you are given two integers (i) and (x), and you must update the array by setting (a_i:= x) persistently . It is guaranteed that (a_i = 0) at the time of each query, and it is guaranteed that (x) divides (n). After performing each query, output the sum of the number of inversions(^{\text{†}}) across all valid permutations. As the answers can be very large, report them modulo (998\,244\,353). (^{\text{∗}})A permutation of length (m) is an array consisting of (m) distinct integers from (1) to (m) in arbitrary order. For example, (2,3,1,5,4) is a permutation, but (1,2,2) is not a permutation ((2) appears twice in the array), and (1,3,4) is also not a permutation ((m=3) but there is a (4) in the array). (^{\text{†}})An inversion in a permutation (p) is a pair of indices ((i, j)) such that (i \lt j) and (p_i \gt p_j). For example, the permutation (4, 1, 3, 2) has (4) inversions: ((1, 2)), ((1, 3)), ((1, 4)), and ((3, 4)). Each test contains multiple test cases. The first line contains the number of test cases (t) ((1 \le t \le 10^4)). The description of the test cases follows. The first line of each testcase contains two integers (n) and (q) ((1 \le n \le 2 \cdot 10^6); (1 \le q \le \min(n, 10^6))) — the length of the array (a) and the number of queries. Each of the next (q) lines contains two integers (i) and (x) ((1 \le i \le n); (1 \le x \le n)). It is guaranteed that (a_i = 0) at the time of each query, and it is guaranteed that (x) divides $$$n

Tutorials

Codeforces Round 1095 (Div. 2) Editorial

Submissions

Submission Id
Author(s)
Index
Submitted
Verdict
Language
Test Set
Tests Passed
Time taken (ms)
Memory Consumed (bytes)
Tags
Rating
372870924 caffeine2ac F April 28, 2026, 4:44 p.m. OK C# 13 TESTS 30 328 93286400
372863080 potato167 F April 28, 2026, 4:15 p.m. OK C++17 (GCC 7-32) TESTS 30 734 17408000
372863017 Fanboymessi F April 28, 2026, 4:15 p.m. OK C++17 (GCC 7-32) TESTS 30 875 50585600
372872283 Iam_Ceighter F April 28, 2026, 4:48 p.m. OK C++17 (GCC 7-32) TESTS 30 906 47411200
372884931 _.rajababu F April 28, 2026, 7:03 p.m. OK C++17 (GCC 7-32) TESTS 30 953 72192000
372892774 Linuyin F April 28, 2026, 8:57 p.m. OK C++17 (GCC 7-32) TESTS 30 1140 36147200
372865649 R_eeee F April 28, 2026, 4:24 p.m. OK C++17 (GCC 7-32) TESTS 30 1390 80281600
372905602 CanadaGoose_imkdldw F April 29, 2026, 3:37 a.m. OK C++17 (GCC 7-32) TESTS 30 1671 92467200
372904851 yxl1 F April 29, 2026, 3:19 a.m. OK C++20 (GCC 13-64) TESTS 30 187 40652800
372898725 dfgsae F April 29, 2026, 12:12 a.m. OK C++20 (GCC 13-64) TESTS 30 203 36249600
372872174 TYP_LongHD F April 28, 2026, 4:48 p.m. OK C++20 (GCC 13-64) TESTS 30 203 43827200
372867309 CPluhPluh F April 28, 2026, 4:30 p.m. OK C++20 (GCC 13-64) TESTS 30 468 28160000
372908268 FantasyNumber F April 29, 2026, 4:40 a.m. OK C++20 (GCC 13-64) TESTS 30 484 64204800
372871096 fidan2005 F April 28, 2026, 4:44 p.m. OK C++20 (GCC 13-64) TESTS 30 500 32153600
372870880 kotatsugame F April 28, 2026, 4:44 p.m. OK C++20 (GCC 13-64) TESTS 30 515 53043200
372864606 rishuraj1397 F April 28, 2026, 4:20 p.m. OK C++20 (GCC 13-64) TESTS 30 531 28160000
372865182 JPMM F April 28, 2026, 4:22 p.m. OK C++20 (GCC 13-64) TESTS 30 531 32768000
372890240 Swammick F April 28, 2026, 8:11 p.m. OK C++20 (GCC 13-64) TESTS 30 625 76288000
372860764 hanmantkurhade77 F April 28, 2026, 4:07 p.m. OK C++23 (GCC 14-64, msys2) TESTS 30 187 61030400
372892585 424479543 F April 28, 2026, 8:52 p.m. OK C++23 (GCC 14-64, msys2) TESTS 30 250 62156800
372904779 banney F April 29, 2026, 3:17 a.m. OK C++23 (GCC 14-64, msys2) TESTS 30 421 30515200
372879630 JessieQY F April 28, 2026, 6:06 p.m. OK C++23 (GCC 14-64, msys2) TESTS 30 484 28262400
372866473 edmondium23 F April 28, 2026, 4:27 p.m. OK C++23 (GCC 14-64, msys2) TESTS 30 500 28262400
372870555 imammadov20577 F April 28, 2026, 4:42 p.m. OK C++23 (GCC 14-64, msys2) TESTS 30 500 32153600
372866805 RustyPanda F April 28, 2026, 4:28 p.m. OK C++23 (GCC 14-64, msys2) TESTS 30 500 32358400
372899092 enslaved F April 29, 2026, 12:27 a.m. OK C++23 (GCC 14-64, msys2) TESTS 30 500 48332800
372866702 onlyfanz F April 28, 2026, 4:28 p.m. OK C++23 (GCC 14-64, msys2) TESTS 30 515 38502400
372899580 L1022 F April 29, 2026, 12:47 a.m. OK C++23 (GCC 14-64, msys2) TESTS 30 515 44339200
372871768 bitplease_ F April 28, 2026, 4:47 p.m. OK Node.js TESTS 30 984 184524800
372867920 Little_Sheep_Yawn F April 28, 2026, 4:32 p.m. OK PyPy 3-64 TESTS 30 890 138956800
372895232 eugenechka.boyko.2_0-0 F April 28, 2026, 10:02 p.m. OK PyPy 3-64 TESTS 30 1875 72499200
372872587 trycatchcry F April 28, 2026, 4:49 p.m. OK Rust 2024 TESTS 30 546 118784000

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