Educational Codeforces Round 187 (Rated for Div. 2)

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ContestId
Name
Phase
Frozen
Duration (Seconds)
Relative Time
Start Time
2203 Educational Codeforces Round 187 (Rated for Div. 2) FINISHED False 7200 4375523 Feb. 25, 2026, 2:35 p.m.

Problems

Solved
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Name
Type
Tags
Community Tag
Rating
( 1364 ) E Probabilistic Card Game PROGRAMMING binary search data structures math ternary search

Alice and Bob have a deck of cards, which is initially empty. They play a game that lasts for (m) rounds. In the (i)-th round, the following events occur: a card with the value (a_i) is added to the deck (it is guaranteed that no card with this value was previously in the deck); if there are fewer than (3) cards in the deck, the round ends; otherwise, Alice chooses a card from the deck; then Bob chooses a card (knowing which card Alice chose; he cannot choose the same one); one more card is chosen from the remaining (i-2) cards uniformly at random; at the end, all three chosen cards are returned to the deck. Let (a) be the value on Alice's card, (b) be the value on Bob's card, and (c) be the value on the randomly chosen card. Then Bob receives: (0) points if (|a - c| \le |b - c|) (where (|x|) denotes the absolute value of (x)); (0) points if card (c) is between cards (a) and (b) (i. e., (a \lt c \lt b) or (b \lt c \lt a)); (|b-c|) points otherwise. Alice's goal in each round is to minimize Bob's expected score, while Bob's goal is to maximize it. What will be the expected score for Bob in each round if both Alice and Bob play optimally? Print the expected score modulo (998\,244\,353). Note that the players minimize or maximize the real value of the expected score, not the result taken modulo (998\,244\,353). The first line contains a single integer ((3 \le m \le 2 \cdot 10^5)) — the number of rounds. The second line contains (m) integers (a_1, a_2, \dots, a_m) ((1 \le a_i \le 10^{12}); all (a_i) are distinct). Print (m-2) integers: the (i)-th number should be equal to the expected score for Bob in the round (i+2) with optimal play from both players modulo (998\,244\,353) (i. e., let the expected score be an irreducible fraction (\frac{x}{y}); you need to output (x \cdot y^{-1} \bmod 998\,244\,353), where (y^{-1}) is such a num

Tutorials

Educational Codeforces Round 187 Editorial

Submissions

Submission Id
Author(s)
Index
Submitted
Verdict
Language
Test Set
Tests Passed
Time taken (ms)
Memory Consumed (bytes)
Tags
Rating
364434240 _Equinox E Feb. 26, 2026, 5:55 a.m. OK C# 13 TESTS 35 562 34201600
364375059 fakeapple E Feb. 25, 2026, 4:30 p.m. OK C++17 (GCC 7-32) TESTS 35 593 2457600
364382734 CrossFire1 E Feb. 25, 2026, 5:09 p.m. OK C++17 (GCC 7-32) TESTS 35 609 18227200
364369227 darkmatter_druid E Feb. 25, 2026, 4:16 p.m. OK C++17 (GCC 7-32) TESTS 35 671 5836800
364369258 gloriali8976 E Feb. 25, 2026, 4:16 p.m. OK C++17 (GCC 7-32) TESTS 35 718 16281600
364420222 Paipai1201 E Feb. 26, 2026, 2:56 a.m. OK C++17 (GCC 7-32) TESTS 35 734 4915200
364371454 hit_ler E Feb. 25, 2026, 4:21 p.m. OK C++17 (GCC 7-32) TESTS 35 734 4915200
364421259 xcplh E Feb. 26, 2026, 3:10 a.m. OK C++17 (GCC 7-32) TESTS 35 734 11264000
364368719 sundaramtiwari9696 E Feb. 25, 2026, 4:14 p.m. OK C++17 (GCC 7-32) TESTS 35 765 2457600
364427440 Pt.ll E Feb. 26, 2026, 4:28 a.m. OK C++17 (GCC 7-32) TESTS 35 765 16793600
364427108 xcplh E Feb. 26, 2026, 4:24 a.m. OK C++17 (GCC 7-32) TESTS 35 812 11264000
364367779 sbsb114 E Feb. 25, 2026, 4:12 p.m. OK C++20 (GCC 13-64) TESTS 35 250 6451200
364405675 mafufo_con_suero E Feb. 25, 2026, 9:33 p.m. OK C++20 (GCC 13-64) TESTS 35 437 16179200
364386146 shendeliliang E Feb. 25, 2026, 5:38 p.m. OK C++20 (GCC 13-64) TESTS 35 437 19353600
364369556 suryanshubansal E Feb. 25, 2026, 4:17 p.m. OK C++20 (GCC 13-64) TESTS 35 484 11571200
364371719 varadaagarwal E Feb. 25, 2026, 4:22 p.m. OK C++20 (GCC 13-64) TESTS 35 500 3379200
364410448 LanceTheDragonTrainer E Feb. 25, 2026, 11:22 p.m. OK C++20 (GCC 13-64) TESTS 35 515 5222400
364423865 YaKei E Feb. 26, 2026, 3:47 a.m. OK C++20 (GCC 13-64) TESTS 35 515 7475200
364385573 shendeliliang E Feb. 25, 2026, 5:33 p.m. OK C++20 (GCC 13-64) TESTS 35 531 19353600
364372078 threethreetwothree E Feb. 25, 2026, 4:23 p.m. OK C++20 (GCC 13-64) TESTS 35 531 40550400
364385151 E49869826 E Feb. 25, 2026, 5:30 p.m. OK C++20 (GCC 13-64) TESTS 35 546 2560000
364378457 Liyuu_ E Feb. 25, 2026, 4:41 p.m. OK C++23 (GCC 14-64, msys2) TESTS 35 265 108236800
364396981 Dr_Zhang E Feb. 25, 2026, 7:28 p.m. OK C++23 (GCC 14-64, msys2) TESTS 35 281 1945600
364424721 CCCCOrz E Feb. 26, 2026, 3:57 a.m. OK C++23 (GCC 14-64, msys2) TESTS 35 281 24064000
364377249 Liyuu_ E Feb. 25, 2026, 4:34 p.m. OK C++23 (GCC 14-64, msys2) TESTS 35 296 108236800
364423881 Codesystem E Feb. 26, 2026, 3:47 a.m. OK C++23 (GCC 14-64, msys2) TESTS 35 312 1843200
364393228 Papaulo E Feb. 25, 2026, 6:45 p.m. OK C++23 (GCC 14-64, msys2) TESTS 35 312 47308800
364384829 limx E Feb. 25, 2026, 5:27 p.m. OK C++23 (GCC 14-64, msys2) TESTS 35 375 2764800
364420781 luo114514 E Feb. 26, 2026, 3:04 a.m. OK C++23 (GCC 14-64, msys2) TESTS 35 375 14540800
364415947 Danielcdo E Feb. 26, 2026, 1:36 a.m. OK C++23 (GCC 14-64, msys2) TESTS 35 390 12902400
364393579 Dr_Zhang E Feb. 25, 2026, 6:49 p.m. OK C++23 (GCC 14-64, msys2) TESTS 35 406 13107200
364369815 SaraZeynalzada E Feb. 25, 2026, 4:17 p.m. OK GNU C11 TESTS 35 1281 7270400
364371414 aykhanasgarov251 E Feb. 25, 2026, 4:21 p.m. OK Java 21 TESTS 35 765 10752000
364411355 aha E Feb. 25, 2026, 11:45 p.m. OK Java 21 TESTS 35 906 16384000
364371650 Mounith22 E Feb. 25, 2026, 4:22 p.m. OK Java 21 TESTS 35 1171 9113600
364368801 khnuray E Feb. 25, 2026, 4:15 p.m. OK Java 21 TESTS 35 1250 46080000
364435310 jdltc E Feb. 26, 2026, 6:06 a.m. OK Java 21 TESTS 35 1562 39219200
364367662 hema13dec03 E Feb. 25, 2026, 4:12 p.m. OK Java 21 TESTS 35 1796 7372800
364385317 vineetiwari E Feb. 25, 2026, 5:31 p.m. OK Java 21 TESTS 35 2421 53555200
364372966 qwon99 E Feb. 25, 2026, 4:25 p.m. OK Java 8 TESTS 35 2156 25702400
364371442 sajjanikhil123 E Feb. 25, 2026, 4:21 p.m. OK Kotlin 1.9 TESTS 35 2328 16691200
364380020 fastem E Feb. 25, 2026, 4:51 p.m. OK PyPy 3-64 TESTS 35 2546 59801600
364429926 IcyGirl E Feb. 26, 2026, 5:01 a.m. OK PyPy 3-64 TESTS 35 2984 46284800
364370509 Anonimmus- E Feb. 25, 2026, 4:19 p.m. OK PyPy 3-64 TESTS 35 3093 58982400
364429137 IcyGirl E Feb. 26, 2026, 4:51 a.m. OK PyPy 3-64 TESTS 35 3203 42598400
364434928 IcyGirl E Feb. 26, 2026, 6:02 a.m. OK PyPy 3-64 TESTS 35 3281 43724800
364374841 yupooh E Feb. 25, 2026, 4:29 p.m. OK PyPy 3-64 TESTS 35 3281 44748800
364368337 21BCE085 E Feb. 25, 2026, 4:14 p.m. OK PyPy 3-64 TESTS 35 3296 76288000
364374048 crown_seeker E Feb. 25, 2026, 4:28 p.m. OK PyPy 3-64 TESTS 35 3343 45670400
364435214 IcyGirl E Feb. 26, 2026, 6:05 a.m. OK PyPy 3-64 TESTS 35 3531 52633600
364372660 Msgnh E Feb. 25, 2026, 4:24 p.m. OK PyPy 3-64 TESTS 35 3718 69939200
364373978 Egor E Feb. 25, 2026, 4:27 p.m. OK Rust 2024 TESTS 35 500 30003200
364383404 Sugar_fan E Feb. 25, 2026, 5:15 p.m. OK Rust 2024 TESTS 35 2953 22630400

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