We will hold Luogu Round 273 on Luogu. This is a Div.1/2 round. English statement will be provided officially. You can click the button to change language.

• Contest URL:
• Div.1: https://www.luogu.com.cn/contest/309087
• Div.2: https://www.luogu.com.cn/contest/309086
• Start Time: 03.01 14:00(UTC+8)
• Duration: 240 minutes
• System: IOI
• Difficulty: CF Div.1/2
• Staffs: VinstaG173, dottle, _istil, OIer1048576, mrsrz, zlxFTH
• Rated range: Div.1 unlimited. Div.2 <=2000 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 272 on Luogu. This is a Div.2 round. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/299754
• Start Time: 02.21 14:00(UTC+8)
• Duration: 270 minutes
• System: IOI
• Difficulty: CF Div.2
• Staffs: zyc070419, ysparkle, 39xiemy, Ybll_, ericzc, Green_Leaves
• Rated range: <=2000 rating on Luogu
• Score distribution: 100-100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 267 on Luogu. This is a Div.2 round. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/282947
• Start Time: 02.11 14:00(UTC+8)
• Duration: 240 minutes
• System: IOI
• Difficulty: CF Div.2
• Staffs: sto_HXY_orz, xiaozha, ukbwyx, danio1029
• Rated range: <=2000 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 249 on Luogu. This is a Div.3 round. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/242706
• Start Time: 11.23 14:00(UTC+8)
• Duration: 210 minutes
• System: IOI
• Difficulty: CF Div.3-4
• Staffs: WaterSun, Leftist_G, StayAlone
• Rated range: <=1600 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 248 on Luogu. This is a Div.1/2 round. English statement will be provided officially. You can click the button to change language.

• Contest URL:
• Div.1: https://www.luogu.com.cn/contest/230986
• Div.2: https://www.luogu.com.cn/contest/276844
• Start Time: 11.09 14:00(UTC+8)
• Duration: 240 minutes
• System: IOI
• Difficulty: similar to CF Div.1/2
• Coordinator: E.Space, Crysfly
• Staffs: ma2021tyoi0037, ty_ak, wangmarui, not_clever_syl, hzy_____
• Rated range: Div.1 unlimited; Div.2 <=2000 rating on Luogu
• Score distribution: 100-100-100-100 for each division

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 243 on Luogu. This is a Div.3 round. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/256849
• Start Time: 10.01 14:00(UTC+8)
• Duration: 210 minutes
• System: IOI
• Difficulty: similar to CF Div.3/4
• Staffs: ykzzldz, Gold14526, yeweiliang
• Rated range: <=1600 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 240 on Luogu. This is a Div.1/Div.2 round sponsored by Hetao Education. English statement will be provided officially. You can click the button to change language.

• Contest URL:
  • Div.1: https://www.luogu.com.cn/contest/273933
  • Div.2: https://www.luogu.com.cn/contest/228479
• Start Time: 09.27 14:00(UTC+8)
• Duration: 240 minutes
• System: IOI
• Difficulty: similar to CF Div.1/2
• Staffs: chenhongrui, zdc123456, -1yks, wxzz, Tony2_CF
• Rated range:
  • Div.1: Unlimited
  • Div.2: <=2000 Rating on Luogu
• Score distribution: 100-100-100-100 for each div

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold 【MX-X19/J22】Mengxiong Weekly on Luogu. This is a Div.1+Div.3 round provided by our collaborator. English statement will be provided by DeepSeek V3. You can switch the language of the problem description.

• Contest URL:
  • Div.1: https://www.luogu.com.cn/contest/273609
  • Div.3: https://www.luogu.com.cn/contest/273610
• Start Time: 09-06 14:00 (GMT+8)
• Duration: 210 minutes
• System: IOI
• Difficulty: Div.1+Div.3
• Staffs: ma2021tyoi0037, Anemones, CutieSmileHaruka, wangmarui, hzy_____, LadyMisserina, Crysfly, StarSilk(ICPC World Finals 2025 Gold Medalist)
• Rated range: Unrated on Luogu
• Score Distribution:
  • Div.1: 100-100-100-100-100
  • Div.3: 100-100-100-100-100
  • The Div.3C will be Div.1A, Div.3D will be Div.1B, etc.

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 237 on Luogu. This is a Div.3 round. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/241168
• Start Time: 08.23 14:00(UTC+8)
• Duration: 210 minutes
• System: IOI
• Difficulty: easier than CF div.3
• Staffs: psgawa, yangyang1000, Ns6Juruo, liuhengyu, molimicha
• Rated range: <=1600 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 238 on Luogu. This is a Div.2 round. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/250409
• Start Time: 08.13 14:00(UTC+8)
• Duration: 240 minutes
• System: IOI
• Difficulty: CF div.2
• Staffs: kdyl, Mr_Az, _cly_, complete_binary_tree, yemuzhe, pyiming
• Rated range: <=2000 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold 【MX-X15/J18】Mengxiong Weekly on Luogu. This is a Div.1+Div.3 round provided by our collaborator. English statement will be provided by DeepSeek V3. You can switch the language of the problem description.

• Contest URL:
  • Div.1: https://www.luogu.com.cn/contest/263176
  • Div.3: https://www.luogu.com.cn/contest/263177
• Start Time: 08-03 14:00 (GMT+8)
• Duration: 210 minutes
• System: IOI
• Difficulty: Div.1+Div.3
• Staffs: _istil, SF1yer, EmpileError, Milkcat2009, Caylex, Kuno_Kako, LMydd0225, 275307894a, StarSilk
• Rated range: Unrated on Luogu
• Score Distribution:
  • Div.1: 100-100-100-100-100
  • Div.3: 100-100-100-100-100
  • The Div.3C will be Div.1A, Div.3D will be Div.1B, etc.

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 235 on Luogu. This is a Div.2 round. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/232544
• Start Time: 08.02 14:00(UTC+8)
• Duration: 240 minutes
• System: IOI
• Difficulty: CF div.2
• Staffs: ma2021tyoi0037, CutieSmileHaruka, ty_ak, wwwza, not_clever_syl, STDJCY, xiaosi4081, wangmarui, E.Space
• Rated range: <=2000 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 234 on Luogu. This is a Div.3 round. English statement will be provided officially. You can click the button to change language.

This competition is modeled after China's CSP-J, which saw over 40,000 junior high and elementary school participants last year.

• Contest URL: https://www.luogu.com.cn/contest/255793
• Start Time: 07.27 14:00(UTC+8)
• Duration: 210 minutes
• System: Non full-feedback. You can get your result only after the contest.
• Difficulty: CF div.3
• Staffs: Coffee_zzz, steven_yummy, Amao_Fox, Sanae, McIron233, SpadeA261, wangmarui, Xuan_HR
• Rated range: <=1600 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold 【MX-X14/J17】Mengxiong Weekly on Luogu. This is a Div.1+Div.3 round provided by our collaborator. English statement will be provided by DeepSeek V3. You can switch the language of the problem description.

• Contest URL:
  • Div.1: https://www.luogu.com.cn/contest/261524
  • Div.3: https://www.luogu.com.cn/contest/261525
• Start Time: 07-26 14:00 (GMT+8)
• Duration: 210 minutes
• System: IOI
• Difficulty: Div.1+Div.3
• Staffs: MYFJCHX, MYJBCHX, aaaaaaqqqqqq, Franklzh, Crysfly, StarSilk
• Rated range: Unrated on Luogu
• Score Distribution:
  • Div.1: 100-100-100-100-100
  • Div.3: 100-100-100-100-100
  • The Div.3C will be Div.1A, Div.3D will be Div.1B, etc.

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 232 on Luogu. This is a Div.2 round. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/241770
• Start Time: 07.16 14:00(UTC+8)
• Duration: 240 minutes
• System: IOI
• Difficulty: CF div.2
• Staffs: ma2021tyoi0037, Lyz09, CutieSmileHaruka, bdzzj, Little09
• Rated range: <=2000 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 231 on Luogu. This is a Div.3 round. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/203883
• Start Time: 07.13 14:00(UTC+8)
• Duration: 210 minutes
• System: IOI
• Difficulty: CF div.3 or easier
• Staffs: _O_v_O_, SF1yer, yingshi, joe_zxq, lostkeytoreach, CaiZi1234, Argvchs, lucasincyber, VinstaG173
• Rated range: <=1600 rating on Luogu
• Score distribution: 100-100-100-100

We will hold 【MX-X13/J16】Mengxiong Weekly (Open) on Luogu. This is a Div.1+Div.3 round provided by our collaborator. English statement will be provided by DeepSeek V3. You can switch the language of the problem description.

• Contest URL:
  • Div.1: https://www.luogu.com.cn/contest/252738
  • Div.3: https://www.luogu.com.cn/contest/252739
• Start Time: 06-29 14:00 (GMT+8)
• Duration: 180 minutes
• System: IOI
• Difficulty: Div.1+Div.3
• Staffs: sszcdjr, Otomachi_Una, rizynvu, SesameSoupO, _istil, StarSilk
• Rated range: Unrated on Luogu
• Score Distribution:
  • Div.1: 100-100-100-100-100
  • Div.3: 100-100-100-100-100
  • The Div.3C will be Div.1A, Div.3D will be Div.1B, etc.

We are looking forward to your participation!

• A tutorial on using Luogu (Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Ynoi 2019 round on Luogu. This is a contest with 4 problems, of Div.1 difficulty, mainly focusing on data structures. Some problems may have been used in previous contests. If you have seen the problems in advance or know their solutions, please do not participate in this contest.

• Contest URL: https://www.luogu.com.cn/contest/253194
• Start Time: 06.24 12:00(UTC+8)
• Duration: 1440 minutes
• System: IOI
• Difficulty: Div.1 difficulty
• Staffs: ODT
• Rated range: Unrated
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu(Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 229 on Luogu. This is a Div.2 round sponsored by <taoliweilai.com>. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/233396
• Start Time: 06.07 14:00(UTC+8)
• Duration: 240 minutes
• System: IOI
• Difficulty: CF div.2
• Staffs: VinstaG173, Kubic
• Rated range: <=2000 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu(Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 228 on Luogu. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/187787
• Start Time: 05.31 14:00(UTC+8)
• Duration: 210 minutes
• System: IOI
• Difficulty: easier than CF div.3
• Staffs: Anemones, gza, the___, BFSDFS123qwq, One_Wan
• Rated range: <=1600 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu(Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

It is clear that our previous announcement has met unreasonable downvotes.

We will hold Luogu Round 227 on Luogu. This is a Div.2 round sponsored by Hetao Education. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/219334
• Start Time: 05.25 14:00(UTC+8)
• Duration: 240 minutes
• System: IOI
• Difficulty: similar to CF Div.2
• Staffs: SoLX, cdx123456, _Hugoi_, born_to_sun, haizhi_w, zzzyyyyhhhhh, lichenxi114, xvtianze
• Rated range: <=2000 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu(Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 227 on Luogu. This is a Div.2 round sponsored by Hetao Education. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/219334
• Start Time: 05.25 14:00(UTC+8)
• Duration: 240 minutes
• System: IOI
• Difficulty: similar to CF Div.2
• Staffs: SoLX, cdx123456, _Hugoi_, born_to_sun, haizhi_w, zzzyyyyhhhhh, lichenxi114, xvtianze
• Rated range: <=2000 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu(Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 223 on Luogu. This is a Div.3 round sponsored by Meracode. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/213624
• Start Time: 05.04 14:00(UTC+8)
• Duration: 210 minutes
• System: IOI
• Difficulty: similar or lower than CF Div.3
• Staffs: zhangrj, lovelyfish, BlackHIG, Nameless_Mist, _O_v_O_, System_Error_, psgawa, VinstaG173
• Rated range: <=1600 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu(Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 224 on Luogu. This is a Div.2 round. English statement will be provided officially. You can click the button to change language.

• Contest URL: https://www.luogu.com.cn/contest/241690
• Start Time: 05.02 14:00(UTC+8)
• Duration: 240 minutes
• System: IOI
• Difficulty: similar to CF Div.2
• Staffs: Ns6Juruo, Kevin0501, _istil, MornStar, E.Space
• Rated range: <=2000 rating on Luogu
• Score distribution: 100-100-100-100

We are looking forward to your participation!

• A tutorial on using Luogu(Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI

We will hold Luogu Round 222 on Luogu. This is a Div.1+2 Round sponsored by Meracode. English statement will be provided officially.

• Contest URL:
  • Div.1: https://www.luogu.com.cn/contest/201695
  • Div.2: https://www.luogu.com.cn/contest/240146
• Start Time: 04.26 14:00(UTC+8)
• Duration: 240 minutes
• System: IOI
• Difficulty: similar to CF Div.1/Div.2
• Staffs: Kevin0501, _saixingzhe_, Milkcat2009, Wf_yjqd, E.Space, Little09, Eclipsar
• Rated range: Div.1 is rated for all; Div.2 is rated for <=2000 rating on Luogu
• Score Distribution:
  • Div.2: 100-100-100-100-100
  • Div.1: 100-100-100-100-50
  • Div.2C will be Div.1A, Div.2D will be Div.1B, Div.2E will be Div.1C.

We are looking forward to your participation!

• A tutorial on using Luogu(Please note that #pragma GCC optimize is temporarily banned for some reason on Luogu.)
• A brief introduction to Chinese NOI