Codeforces Round 1070 (Div. 2)

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ContestId
Name
Phase
Frozen
Duration (Seconds)
Relative Time
Start Time
2176 Codeforces Round 1070 (Div. 2) FINISHED False 7200 10941923 Dec. 11, 2025, 2:35 p.m.

Problems

Solved
Index
Name
Type
Tags
Community Tag
Rating
( 1463 ) F Omega Numbers PROGRAMMING bitmasks dp math number theory

For a given number (n), consider the function (\omega(n)), which is equal to the number of unique prime numbers in the prime factorization of the number (n). For example, (\omega (12) = \omega (2^2 \cdot 3) = 2). And (\omega (120) = \omega (2^3 \cdot 3 \cdot 5) = 3). For an array of natural numbers (a) and a natural number (k), we define (\operatorname{f}(a, k) = \sum_{i < j} \omega(a_i \cdot a_j)^k) for all (i < j). You are given an array of natural numbers (a) of length (n) and a natural number (k). Calculate (\operatorname{f}(a, k)) modulo (998\,244\,353). 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 test case contains 2 integers (n) and (k) ((1 \leq n \leq 2 \cdot 10^5, 1 \leq k \leq 10^9)) —the length of the array (a) and the exponent of the operation, respectively. The second line of each test case contains (n) natural numbers (a_1, a_2, \ldots, a_n) ((1 \leq a_i \leq n)) —the array (a). It is guaranteed that the sum of (n) across all test cases does not exceed (2 \cdot 10^5). For each test case, output a single line containing an integer — the value of the function (\operatorname{f}(a, k)) modulo (998\,244\,353). Explanation of the first test case example: For any pair ((i,j)), the value (\omega(x)) for the product is (\omega(3^2) = 1). There are a total of (6) pairs, and the exponent is (1). The final answer is (6). Explanation of the second test case example: In any pair of the second test case, the product of the numbers in the pair equals (1), so the number of primes in it is (0). Therefore, the final answer is also (0). Explanation of the third test case example: Consider all pairs ((i,j)): ((1,2)): the product of the numbers at positions (1) and (2)

Tutorials

Codeforces Round 1070 (Div.2) Editorial

Submissions

Submission Id
Author(s)
Index
Submitted
Verdict
Language
Test Set
Tests Passed
Time taken (ms)
Memory Consumed (bytes)
Tags
Rating
353086538 -firefly- F Dec. 11, 2025, 4:21 p.m. OK C# 13 TESTS 80 1453 65126400
353086052 SachinScripts F Dec. 11, 2025, 4:20 p.m. OK C++17 (GCC 7-32) TESTS 80 218 6860800
353086529 Acheronl F Dec. 11, 2025, 4:21 p.m. OK C++17 (GCC 7-32) TESTS 80 250 18022400
353085682 Profesor_programiranja F Dec. 11, 2025, 4:19 p.m. OK C++17 (GCC 7-32) TESTS 80 265 3379200
353129134 sunyx F Dec. 12, 2025, 12:52 a.m. OK C++17 (GCC 7-32) TESTS 87 281 26112000
353091388 sahilsi F Dec. 11, 2025, 4:31 p.m. OK C++17 (GCC 7-32) TESTS 80 312 15257600
353092325 vivektyagi08 F Dec. 11, 2025, 4:33 p.m. OK C++17 (GCC 7-32) TESTS 80 328 27340800
353087874 with_care F Dec. 11, 2025, 4:24 p.m. OK C++17 (GCC 7-32) TESTS 80 421 9011200
353088270 Dipanshu07r F Dec. 11, 2025, 4:25 p.m. OK C++17 (GCC 7-32) TESTS 80 421 25292800
353086818 Terme F Dec. 11, 2025, 4:22 p.m. OK C++17 (GCC 7-32) TESTS 80 421 69734400
353092293 Terrobyte-sama F Dec. 11, 2025, 4:33 p.m. OK C++17 (GCC 7-32) TESTS 80 437 38707200
353128694 oranger_20 F Dec. 12, 2025, 12:36 a.m. OK C++20 (GCC 13-64) TESTS 87 109 13926400
353101995 Rubikun F Dec. 11, 2025, 5:57 p.m. OK C++20 (GCC 13-64) TESTS 80 140 4300800
353084012 Great_coder003 F Dec. 11, 2025, 4:15 p.m. OK C++20 (GCC 13-64) TESTS 80 140 5734400
353146665 acccccccc F Dec. 12, 2025, 5:47 a.m. OK C++20 (GCC 13-64) TESTS 87 156 8089600
353129856 fisher199 F Dec. 12, 2025, 1:16 a.m. OK C++20 (GCC 13-64) TESTS 87 156 12492800
353101393 Rubikun F Dec. 11, 2025, 5:53 p.m. OK C++20 (GCC 13-64) TESTS 80 218 4300800
353089526 Phan_minh_Duc F Dec. 11, 2025, 4:28 p.m. OK C++20 (GCC 13-64) TESTS 80 218 8089600
353084067 McPqndq F Dec. 11, 2025, 4:15 p.m. OK C++20 (GCC 13-64) TESTS 80 234 1638400
353142859 infCraft F Dec. 12, 2025, 5:16 a.m. OK C++20 (GCC 13-64) TESTS 87 234 7475200
353088327 azim_7000_ F Dec. 11, 2025, 4:25 p.m. OK C++20 (GCC 13-64) TESTS 80 234 59801600
353125457 hungchi17 F Dec. 11, 2025, 10:43 p.m. OK C++23 (GCC 14-64, msys2) TESTS 87 78 2457600
353099063 415411 F Dec. 11, 2025, 5:40 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 78 2457600
353148458 gooonn F Dec. 12, 2025, 6:07 a.m. OK C++23 (GCC 14-64, msys2) TESTS 87 93 2457600
353100023 toufiqhasankiron F Dec. 11, 2025, 5:46 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 125 2457600
353099224 415411 F Dec. 11, 2025, 5:41 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 125 2457600
353103410 snuzh F Dec. 11, 2025, 6:06 p.m. OK C++23 (GCC 14-64, msys2) TESTS 82 125 7475200
353090186 Dulat-E-009-.28 F Dec. 11, 2025, 4:29 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 140 6963200
353091969 wojtekm4726 F Dec. 11, 2025, 4:32 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 156 7475200
353100417 Luis_AQM F Dec. 11, 2025, 5:48 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 156 14540800
353143166 -msu- F Dec. 12, 2025, 5:19 a.m. OK C++23 (GCC 14-64, msys2) TESTS 87 171 6963200
353090222 whiteduke69 F Dec. 11, 2025, 4:29 p.m. OK GNU C11 TESTS 80 546 33792000
353091660 joxamp3 F Dec. 11, 2025, 4:32 p.m. OK Go TESTS 80 484 45363200
353148741 __baozii__ F Dec. 12, 2025, 6:10 a.m. OK Go TESTS 87 625 43929600
353101975 penny_ka_leoNerd F Dec. 11, 2025, 5:57 p.m. OK Java 21 TESTS 80 1218 50892800
353089677 Vishalll_ F Dec. 11, 2025, 4:28 p.m. OK Java 8 TESTS 80 1406 73830400
353104868 arvindf232 F Dec. 11, 2025, 6:16 p.m. OK Kotlin 1.7 TESTS 82 1640 212684800
353102017 SalicylicAcid F Dec. 11, 2025, 5:57 p.m. OK PyPy 3 TESTS 80 1390 168960000
353092877 shadow4720 F Dec. 11, 2025, 4:34 p.m. OK PyPy 3-64 TESTS 80 593 55193600
353092969 a_cedia F Dec. 11, 2025, 4:34 p.m. OK PyPy 3-64 TESTS 80 796 65536000
353116576 jeroenodb F Dec. 11, 2025, 8:04 p.m. OK PyPy 3-64 TESTS 86 1109 46080000
353116885 jeroenodb F Dec. 11, 2025, 8:08 p.m. OK PyPy 3-64 TESTS 87 1140 45977600
353122673 KentShnurnikova F Dec. 11, 2025, 9:35 p.m. OK PyPy 3-64 TESTS 87 1484 445440000
353084290 SumitKundu F Dec. 11, 2025, 4:16 p.m. OK PyPy 3-64 TESTS 80 1515 196096000
353106956 Ayis137 F Dec. 11, 2025, 6:30 p.m. OK PyPy 3-64 TESTS 83 1562 78848000
353090824 Sacred_Conqurer F Dec. 11, 2025, 4:30 p.m. OK PyPy 3-64 TESTS 80 1640 60313600
353083081 LMeyling F Dec. 11, 2025, 4:13 p.m. OK PyPy 3-64 TESTS 80 1812 63590400
353111026 PP2412 F Dec. 11, 2025, 7:05 p.m. OK Python 3 TESTS 86 2078 66150400

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