Codeforces Round 1069 (Div. 1)

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ContestId
Name
Phase
Frozen
Duration (Seconds)
Relative Time
Start Time
2174 Codeforces Round 1069 (Div. 1) FINISHED False 7200 11396723 Dec. 6, 2025, 8:15 a.m.

Problems

Solved
Index
Name
Type
Tags
Community Tag
Rating
( 990 ) C2 Beautiful Patterns (Hard Version) PROGRAMMING math probabilities

This is the hard version of the problem. The difference between the versions is that in this version, (n \le 2 \cdot 10^5). You can hack only if you solved all versions of this problem. Upon entering the ancient palace "Palindrome-Palace", you noticed that there are peculiar patterns on its walls. The pattern is a mosaic of size (1 \times n) made of pebbles, each painted in one of (m) different colors. The correctness of an arbitrary mosaic (s) is defined as the number of non-empty subsegments of (s) that are palindromes. The beauty of the mosaic is defined as the square of its correctness . For example, for the mosaic rgrb , there are five palindromic subsegments: r , g , r , b , and rgr . Therefore, its correctness is (5), and its beauty is (25). While wandering through this palace, you wondered: what is the expected value of the beauty of the mosaic if the color of each of the (n) pebbles is chosen uniformly and independently of the colors of the other pebbles? Print the answer modulo prime (p). Each test contains multiple test cases. The first line contains the number of test cases (t) ((1 \le t \le 1000)). The description of the test cases follows. The only line of each test case contains 3 integers (n), (m), and (p) ((1 \leq n \leq 2 \cdot 10^5); (1 \leq m \leq 10^7); (m < p < 10^9)) representing the length of the mosaic, the number of different colors of pebbles, and the modulus for which the answer needs to be computed. It is guaranteed that (p) is a prime number. It is also guaranteed that the sum of (n) across all test cases does not exceed (10^6). For each test case, output the expected beauty of the mosaic modulo (p). Formally, let (x = p). It can be shown that the exact answer can be expressed as an irreducible fraction (\frac{y}{z}), where (y) and (z) are integers and (z \not \equiv 0 \pmod{x}). Output the integer equal to $$$y \cdot z^{-1}

Tutorials

Codeforces Round 1069 Editorial

Submissions

Submission Id
Author(s)
Index
Submitted
Verdict
Language
Test Set
Tests Passed
Time taken (ms)
Memory Consumed (bytes)
Tags
Rating
352231947 -firefly- C2 Dec. 6, 2025, 9:51 a.m. OK C# 13 TESTS 43 187 11161600
352236879 Sacharlemagne C2 Dec. 6, 2025, 10:06 a.m. OK C++17 (GCC 7-32) TESTS 43 78 1638400
352232026 Kieray C2 Dec. 6, 2025, 9:51 a.m. OK C++17 (GCC 7-32) TESTS 43 78 1638400
352234646 Anixes C2 Dec. 6, 2025, 9:59 a.m. OK C++17 (GCC 7-32) TESTS 43 78 96256000
352232875 HaPpY1213 C2 Dec. 6, 2025, 9:54 a.m. OK C++17 (GCC 7-32) TESTS 43 93 102400
352235011 lijunyi C2 Dec. 6, 2025, 10 a.m. OK C++17 (GCC 7-32) TESTS 43 93 2560000
352285371 krio131 C2 Dec. 6, 2025, 4:12 p.m. OK C++17 (GCC 7-32) TESTS 43 109 102400
352281917 QWQcoding C2 Dec. 6, 2025, 3:47 p.m. OK C++17 (GCC 7-32) TESTS 43 109 4915200
352232469 Max_s_xaM C2 Dec. 6, 2025, 9:53 a.m. OK C++17 (GCC 7-32) TESTS 43 109 5324800
352238813 fft_ntt C2 Dec. 6, 2025, 10:11 a.m. OK C++17 (GCC 7-32) TESTS 43 109 6451200
352233620 luka.heric C2 Dec. 6, 2025, 9:56 a.m. OK C++17 (GCC 7-32) TESTS 43 125 102400
352261794 yangchang C2 Dec. 6, 2025, 1:26 p.m. OK C++20 (GCC 13-64) TESTS 43 46 102400
352233643 sunkaihuan C2 Dec. 6, 2025, 9:56 a.m. OK C++20 (GCC 13-64) TESTS 43 46 9625600
352315013 surajchip2 C2 Dec. 6, 2025, 8:47 p.m. OK C++20 (GCC 13-64) TESTS 44 62 0
352203581 Zhou_Yuan C2 Dec. 6, 2025, 8:43 a.m. OK C++20 (GCC 13-64) TESTS 43 62 102400
352237073 aoliao_lovely C2 Dec. 6, 2025, 10:06 a.m. OK C++20 (GCC 13-64) TESTS 43 62 1638400
352200190 SDSXC C2 Dec. 6, 2025, 8:37 a.m. OK C++20 (GCC 13-64) TESTS 43 62 4915200
352225903 Kude C2 Dec. 6, 2025, 9:33 a.m. OK C++20 (GCC 13-64) TESTS 43 78 0
352211346 DSCS2009 C2 Dec. 6, 2025, 8:58 a.m. OK C++20 (GCC 13-64) TESTS 43 78 0
352316672 gortomi C2 Dec. 6, 2025, 9:16 p.m. OK C++20 (GCC 13-64) TESTS 44 78 102400
352281474 BurnedChicken C2 Dec. 6, 2025, 3:43 p.m. OK C++20 (GCC 13-64) TESTS 43 78 102400
352239596 KobicGend C2 Dec. 6, 2025, 10:13 a.m. OK C++23 (GCC 14-64, msys2) TESTS 43 46 0
352236678 white_unicorn C2 Dec. 6, 2025, 10:05 a.m. OK C++23 (GCC 14-64, msys2) TESTS 43 46 102400
352218647 CHATTY-Bebob C2 Dec. 6, 2025, 9:15 a.m. OK C++23 (GCC 14-64, msys2) TESTS 43 46 102400
352238985 while_zeze C2 Dec. 6, 2025, 10:12 a.m. OK C++23 (GCC 14-64, msys2) TESTS 43 46 40140800
352224743 ApurbaKumarShow C2 Dec. 6, 2025, 9:30 a.m. OK C++23 (GCC 14-64, msys2) TESTS 43 62 0
352320833 uk639 C2 Dec. 6, 2025, 10:42 p.m. OK C++23 (GCC 14-64, msys2) TESTS 44 62 102400
352224530 tkrawczy C2 Dec. 6, 2025, 9:30 a.m. OK C++23 (GCC 14-64, msys2) TESTS 43 62 102400
352218594 Nyaan C2 Dec. 6, 2025, 9:15 a.m. OK C++23 (GCC 14-64, msys2) TESTS 43 62 102400
352225831 Include_Z_F_R_ C2 Dec. 6, 2025, 9:33 a.m. OK C++23 (GCC 14-64, msys2) TESTS 43 62 3276800
352225824 cooluo C2 Dec. 6, 2025, 9:33 a.m. OK C++23 (GCC 14-64, msys2) TESTS 43 62 6963200
352211420 gua069 C2 Dec. 6, 2025, 8:59 a.m. OK Java 8 TESTS 43 265 0
352232427 a_cedia C2 Dec. 6, 2025, 9:52 a.m. OK PyPy 3-64 TESTS 43 125 7065600
352208186 Ayis137 C2 Dec. 6, 2025, 8:52 a.m. OK PyPy 3-64 TESTS 43 125 7884800
352319581 ndelisle C2 Dec. 6, 2025, 10:14 p.m. OK PyPy 3-64 TESTS 44 171 7372800
352213690 golomb C2 Dec. 6, 2025, 9:03 a.m. OK PyPy 3-64 TESTS 43 203 15155200
352291790 smz.26 C2 Dec. 6, 2025, 5:04 p.m. OK PyPy 3-64 TESTS 44 218 30310400
352337709 maxymien C2 Dec. 7, 2025, 5:03 a.m. OK PyPy 3-64 TESTS 44 265 12390400
352210963 gawkmaster069 C2 Dec. 6, 2025, 8:58 a.m. OK PyPy 3-64 TESTS 43 281 4812800
352298546 alphaGem C2 Dec. 6, 2025, 6:01 p.m. OK PyPy 3-64 TESTS 44 953 16179200
352277909 siddhantbashisth C2 Dec. 6, 2025, 3:16 p.m. OK Python 3 TESTS 43 1234 4608000
352232488 toomer C2 Dec. 6, 2025, 9:53 a.m. OK Rust 2021 TESTS 43 93 102400
352214764 sansen C2 Dec. 6, 2025, 9:06 a.m. OK Rust 2021 TESTS 43 187 102400
352198724 Monster027 C2 Dec. 6, 2025, 8:34 a.m. OK Rust 2024 TESTS 43 218 0

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