Codeforces Round 1053 (Div. 1)

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ContestId
Name
Phase
Frozen
Duration (Seconds)
Relative Time
Start Time
2150 Codeforces Round 1053 (Div. 1) FINISHED False 11700 17691923 Sept. 24, 2025, 11:35 a.m.

Problems

Solved
Index
Name
Type
Tags
Community Tag
Rating
( 1012 ) E1 Hidden Single (Version 1) PROGRAMMING divide and conquer interactive math probabilities sortings

The two versions have different constraints on (t), (n), and the maximum number of queries, and solving one of the two versions does not necessarily solve the other. You may want to read both versions. Hacks are disabled in both versions. This is an interactive problem. There is a hidden array (a_1, a_2, \ldots, a_{2n-1}) containing all the numbers from (1) to (n), and all of them appear twice except one (which only appears once). You can ask queries in the following format, where (S) is a subset of (\{1, 2, \ldots, 2n-1\}) and (x) is an integer in (1, n): (ask(S, x)): does there exist (i \in S) such that (a_i = x)? Find the number appearing exactly once, using at most (4n + 2 \lceil \log_2 n \rceil) queries. You don't need to find its position. Note that the interactor is not adaptive, which means that the hidden array does not depend on the queries you make. Each test contains multiple test cases. The first line contains the number of test cases (t) ((1 \le t \le 4000)). The description of the test cases follows. The first line of each test case contains a single integer (n) ((1 \le n \le 300)) — the maximum value in the hidden array (a_1, a_2, \ldots, a_{2n-1}). It is guaranteed that the sum of (n^2) over all test cases does not exceed (4 \cdot 10^5). There are exactly (80) tests in this problem (including the example). For each test case, first read a single integer (n). If the integer you read is (-1), it means that the answer to the previous test case was wrong, and you should exit immediately. You may ask up to (4n + 2 \lceil \log_2 n \rceil) queries in each test case. To ask a query, print a line in the format (? x |S| S_1 S_2 ... S_|S|) with (1 \leq x \leq n), (1 \leq S_1, S_2, \ldots, S_{|S|} \leq 2n-1), and all the (S_i) distinct. As a response to the query, you will get (1) if the answer is yes, (0) if the

Tutorials

Editorial of Codeforces Round 1053 (Div. 1, Div. 2)

Submissions

Submission Id
Author(s)
Index
Submitted
Verdict
Language
Test Set
Tests Passed
Time taken (ms)
Memory Consumed (bytes)
Tags
Rating
340192690 HaramuraNodoka E1 Sept. 24, 2025, 1:33 p.m. OK C++17 (GCC 7-32) TESTS 80 765 102400
340185891 potato167 E1 Sept. 24, 2025, 1:10 p.m. OK C++17 (GCC 7-32) TESTS 80 780 102400
340269728 xvchongyv E1 Sept. 25, 2025, 12:50 a.m. OK C++17 (GCC 7-32) TESTS 80 781 102400
340244696 AA-2007 E1 Sept. 24, 2025, 6:29 p.m. OK C++17 (GCC 7-32) TESTS 80 781 102400
340202144 lnw143 E1 Sept. 24, 2025, 2:09 p.m. OK C++17 (GCC 7-32) TESTS 80 812 307200
340242383 AA-2007 E1 Sept. 24, 2025, 6:15 p.m. OK C++17 (GCC 7-32) TESTS 80 827 102400
340265759 zac2010 E1 Sept. 24, 2025, 11:26 p.m. OK C++17 (GCC 7-32) TESTS 80 827 307200
340275421 _l_l_ E1 Sept. 25, 2025, 2:04 a.m. OK C++17 (GCC 7-32) TESTS 80 828 102400
340242528 AA-2007 E1 Sept. 24, 2025, 6:16 p.m. OK C++17 (GCC 7-32) TESTS 80 828 102400
340227203 leukocyte E1 Sept. 24, 2025, 5:01 p.m. OK C++17 (GCC 7-32) TESTS 80 843 102400
340210687 Nextby E1 Sept. 24, 2025, 2:43 p.m. OK C++20 (GCC 13-64) TESTS 80 562 102400
340219627 juju054 E1 Sept. 24, 2025, 4:04 p.m. OK C++20 (GCC 13-64) TESTS 80 593 102400
340263112 jackson.souza E1 Sept. 24, 2025, 10:07 p.m. OK C++20 (GCC 13-64) TESTS 80 624 102400
340194947 Revived_xryjr233 E1 Sept. 24, 2025, 1:41 p.m. OK C++20 (GCC 13-64) TESTS 80 640 102400
340272486 juju054 E1 Sept. 25, 2025, 1:25 a.m. OK C++20 (GCC 13-64) TESTS 80 655 102400
340263581 jackson.souza E1 Sept. 24, 2025, 10:20 p.m. OK C++20 (GCC 13-64) TESTS 80 655 102400
340272330 lucky_clover_ E1 Sept. 25, 2025, 1:23 a.m. OK C++20 (GCC 13-64) TESTS 80 687 102400
340208929 maxplus E1 Sept. 24, 2025, 2:37 p.m. OK C++20 (GCC 13-64) TESTS 80 687 102400
340273031 juju054 E1 Sept. 25, 2025, 1:32 a.m. OK C++20 (GCC 13-64) TESTS 80 702 0
340187548 sevlll777 E1 Sept. 24, 2025, 1:15 p.m. OK C++20 (GCC 13-64) TESTS 80 702 102400
340212360 Senku E1 Sept. 24, 2025, 2:48 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 625 0
340212857 Proof_by_QED E1 Sept. 24, 2025, 2:49 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 671 0
340198158 TBWW E1 Sept. 24, 2025, 1:53 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 671 0
340197662 ksun48 E1 Sept. 24, 2025, 1:51 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 686 102400
340235467 exgcd E1 Sept. 24, 2025, 5:27 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 734 102400
340233339 vedantkohad E1 Sept. 24, 2025, 5:14 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 749 102400
340187302 noimi E1 Sept. 24, 2025, 1:14 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 765 0
340273215 Benq E1 Sept. 25, 2025, 1:33 a.m. OK C++23 (GCC 14-64, msys2) TESTS 80 765 102400
340188834 maroonrk E1 Sept. 24, 2025, 1:20 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 765 102400
340246323 NickMish E1 Sept. 24, 2025, 6:39 p.m. OK C++23 (GCC 14-64, msys2) TESTS 80 780 0
340196320 arvindf232 E1 Sept. 24, 2025, 1:46 p.m. OK Kotlin 2.2 TESTS 80 1343 1740800
340196220 toam E1 Sept. 24, 2025, 1:46 p.m. OK PyPy 3-64 TESTS 80 2359 9728000
340202949 bribritt E1 Sept. 24, 2025, 2:14 p.m. OK PyPy 3-64 TESTS 80 2483 9216000
340236428 VitalyKo E1 Sept. 24, 2025, 5:33 p.m. OK PyPy 3-64 TESTS 80 2702 10342400
340194597 hirayuu_cf E1 Sept. 24, 2025, 1:40 p.m. OK PyPy 3-64 TESTS 80 2718 9625600
340257053 golomb E1 Sept. 24, 2025, 8:19 p.m. OK PyPy 3-64 TESTS 80 3203 11264000
340186353 __baozii__ E1 Sept. 24, 2025, 1:11 p.m. OK PyPy 3-64 TESTS 80 3406 11059200

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