| #2001 | Tropical GardenIOI 2011 Day 1 | |
| #2002 | RaceIOI 2011 Day 1 | |
| #2003 | Rice HubIOI 2011 Day 1 | |
| #2004 | Crocodile's Underground CityIOI 2011 Day 2 | |
| #2005 | Dancing ElephantsIOI 2011 Day 2 | |
| #2006 | ParrotsIOI 2011 Day 2Communication | |
| #2007 | 格雷码CSP-S 2019 | |
| #2008 | 括号树CSP-S 2019 | |
| #2009 | 树上的数CSP-S 2019 | |
| #2010 | Emiya 家今天的饭CSP-S 2019 | |
| #2011 | 划分CSP-S 2019 | |
| #2012 | 树的重心CSP-S 2019 | |
| #2013 | 儒略日CSP-S 2020 | |
| #2014 | 动物园CSP-S 2020 | |
| #2015 | 函数调用CSP-S 2020 | |
| #2016 | 贪吃蛇CSP-S 2020 | |
| #2017 | 排水系统NOIP 2020 | |
| #2018 | 字符串匹配NOIP 2020 | |
| #2019 | 移球游戏NOIP 2020 | |
| #2020 | 微信步数NOIP 2020 | |
| #2021 | 有源汇有上下界最小费用最大流（随机数据） | |
| #2022 | United Cows of Farmer JohnUSACO 2021 US Open Platinum | |
| #2023 | Routing SchemesUSACO 2021 US Open Platinum | |
| #2024 | Balanced SubsetsUSACO 2021 US Open Platinum | |
| #2025 | No Time to DryUSACO 2021 US February Platinum | |
| #2026 | Minimizing EdgesUSACO 2021 February Platinum | |
| #2027 | Counting GraphsUSACO 2021 February Platinum | |
| #2028 | Sum of DistancesUSACO 2021 January Platinum | |
| #2029 | Minimum Cost PathsUSACO 2021 January Platinum | |
| #2030 | Paint by LettersUSACO 2021 January Platinum | |
| #2037 | Mutant VaccineWaterloo Winter 2021 Local | |
| #2038 | Sorting DeviceWaterloo Winter 2021 Local | |
| #2039 | BubblesWaterloo Winter 2021 Local | |
| #2040 | Physical DistancingWaterloo Winter 2021 Local | |
| #2041 | Game ShowWaterloo Winter 2021 Local | |
| #2042 | The BalanceEhime Regional 2004 | |
| #2043 | Make a SequenceEhime Regional 2004 | |
| #2044 | Leaky CryptographyEhime Regional 2004 | |
| #2045 | Pathological PathsEhime Regional 2004 | |
| #2046 | Confusing Login NamesEhime Regional 2004 | |
| #2047 | Dice PuzzleEhime Regional 2004 | |
| #2048 | Color the MapEhime Regional 2004 | |
| #2049 | Inherit the SpheresEhime Regional 2004 | |
| #2050 | Crossing PrismsEhime Regional 2004 | |
| #2051 | Count The OnesEast Siberian Subregional 2016 | |
| #2052 | CratersEast Siberian Subregional 2016 | |
| #2053 | Closing CeremonyEast Siberian Subregional 2016 | |
| #2054 | SkyscrapersEast Siberian Subregional 2016 | |
| #2055 | BlackboardEast Siberian Subregional 2016 | |
| #2056 | Buddy NumbersEast Siberian Subregional 2016 | |
| #2057 | GmoogleEast Siberian Subregional 2016 | |
| #2058 | GeneratorEast Siberian Subregional 2016 | |
| #2059 | AdditionEast Siberian Subregional 2016Interactive | |
| #2060 | White MageEast Siberian Subregional 2016 | |
| #2061 | InspectionEast Siberian Subregional 2016 | |
| #2062 | Fibonacci EquationEast Siberian Subregional 2016 | |
| #2063 | Alternative AccountsPetrozavodsk Winter 2020 Day 9Yuhao Du Contest | |
| #2064 | Bitset MasterPetrozavodsk Winter 2020 Day 9Yuhao Du Contest | |
| #2065 | Cyclic DistancePetrozavodsk Winter 2020 Day 9Yuhao Du Contest | |
| #2066 | Data Structure QuizPetrozavodsk Winter 2020 Day 9Yuhao Du ContestYnoi 2009 | |
| #2067 | Evil SubsequencePetrozavodsk Winter 2020 Day 9Yuhao Du Contest | |
| #2068 | Fast as RyserPetrozavodsk Winter 2020 Day 9Yuhao Du Contest | |
| #2069 | Geometry PTSDPetrozavodsk Winter 2020 Day 9Yuhao Du Contest | |
| #2070 | Heavy StonesPetrozavodsk Winter 2020 Day 9Yuhao Du Contest | |
| #2071 | Interesting GamePetrozavodsk Winter 2020 Day 9Yuhao Du Contest | |
| #2072 | Junk ProblemPetrozavodsk Winter 2020 Day 9Yuhao Du Contest | |
| #2073 | Knowledge-Oriented ProblemPetrozavodsk Winter 2020 Day 9Yuhao Du Contest | |
| #2074 | LCM SumPetrozavodsk Winter 2020 Day 9Yuhao Du Contest | |
| #2096 | FestivalXIX Olimpiada Informatyczna – I etap | |
| #2097 | LettersXIX Olimpiada Informatyczna – I etap | |
| #2098 | DistanceXIX Olimpiada Informatyczna – I etap | |
| #2099 | RendezvousXIX Olimpiada Informatyczna – I etap | |
| #2100 | WellXIX Olimpiada Informatyczna – I etap | |