| #803 | Tree Orientation7th BSUIR Open Programming Championship FinalLesnoe Ozero Workshop 2017 Day 1 | |
| #804 | A Masterpiece7th BSUIR Open Programming Championship FinalLesnoe Ozero Workshop 2017 Day 1 | |
| #805 | Auction7th BSUIR Open Programming Championship FinalLesnoe Ozero Workshop 2017 Day 1 | |
| #806 | Deck Building7th BSUIR Open Programming Championship FinalLesnoe Ozero Workshop 2017 Day 1 | |
| #807 | The secret of betting7th BSUIR Open Programming Championship FinalLesnoe Ozero Workshop 2017 Day 1 | |
| #808 | Financial Reports7th BSUIR Open Programming Championship FinalLesnoe Ozero Workshop 2017 Day 1 | |
| #809 | Moore's Law7th BSUIR Open Programming Championship FinalLesnoe Ozero Workshop 2017 Day 1 | |
| #810 | Plagiarism7th BSUIR Open Programming Championship FinalLesnoe Ozero Workshop 2017 Day 1 | |
| #811 | Number builder7th BSUIR Open Programming Championship FinalLesnoe Ozero Workshop 2017 Day 1 | |
| #812 | Find a triangle7th BSUIR Open Programming Championship FinalLesnoe Ozero Workshop 2017 Day 1Interactive | |
| #823 | Balanced ParenthesesCMU High School Programming Contest 2019 | |
| #824 | Too Many Queens in the KitchenCMU High School Programming Contest 2019 | |
| #825 | SUDOKUCMU High School Programming Contest 2019 | |
| #826 | Use the Force, LuCMU High School Programming Contest 2019 | |
| #827 | Repeating DecimalsCMU High School Programming Contest 2019 | |
| #828 | Palindrome ParsingCMU High School Programming Contest 2019 | |
| #829 | Highest Density SquareCMU High School Programming Contest 2019 | |
| #831 | Airplane CliquesPetrozavodsk Winter 2020 Day 3300iq Contest 3 | |
| #832 | Best TreePetrozavodsk Winter 2020 Day 3300iq Contest 3 | |
| #833 | Cells BlockingPetrozavodsk Winter 2020 Day 3300iq Contest 3 | |
| #834 | Disjoint LISPetrozavodsk Winter 2020 Day 3300iq Contest 3 | |
| #835 | Easy WinPetrozavodsk Winter 2020 Day 3300iq Contest 3 | |
| #836 | Farm of MonstersPetrozavodsk Winter 2020 Day 3300iq Contest 3 | |
| #837 | Giant PenguinPetrozavodsk Winter 2020 Day 3300iq Contest 3 | |
| #838 | Horrible CyclesPetrozavodsk Winter 2020 Day 3300iq Contest 3 | |
| #839 | Ignore SubmasksPetrozavodsk Winter 2020 Day 3300iq Contest 3 | |
| #840 | Just CountingPetrozavodsk Winter 2020 Day 3300iq Contest 3 | |
| #841 | 树状数组 | |
| #842 | 精灵之环 | |
| #843 | 道路规划 | |
| #844 | 空间切割 | |
| #845 | 御坂网络 | |
| #846 | 传送门 | |
| #847 | 游戏 | |
| #848 | 组合数 | |
| #849 | 瘟疫公司 | |
| #850 | Edit Distance Yet AgainPetrozavodsk Winter 2021 Day 1 | |
| #851 | (Almost) Fair Cake-CuttingPetrozavodsk Winter 2021 Day 1 | |
| #852 | JellyfishPetrozavodsk Winter 2021 Day 1 | |
| #853 | Flat OrganizationPetrozavodsk Winter 2021 Day 1 | |
| #854 | Archer VladPetrozavodsk Winter 2021 Day 1 | |
| #855 | A Very Different WordPetrozavodsk Winter 2021 Day 1 | |
| #856 | CactusPetrozavodsk Winter 2021 Day 1 | |
| #857 | Social DistancingPetrozavodsk Winter 2021 Day 1 | |
| #858 | GCD vs. XORPetrozavodsk Winter 2021 Day 1 | |
| #859 | CivilizationsPetrozavodsk Winter 2021 Day 1 | |
| #860 | We apologize for any inconveniencePetrozavodsk Winter 2021 Day 1 | |
| #861 | Patrol DronePetrozavodsk Winter 2021 Day 1 | |
| #862 | Social JusticePetrozavodsk Winter 2021 Day 1 | |
| #863 | Adjacent RooksPetrozavodsk Winter 2021 Day 2 | |
| #864 | Beautiful PermutationPetrozavodsk Winter 2021 Day 2 | |
| #865 | Cartesian MSTPetrozavodsk Winter 2021 Day 2 | |
| #866 | Display of SpringsPetrozavodsk Winter 2021 Day 2Interactive | |
| #867 | Even IntervalsPetrozavodsk Winter 2021 Day 2 | |
| #868 | Friendship CirclesPetrozavodsk Winter 2021 Day 2 | |
| #869 | Game on a TreePetrozavodsk Winter 2021 Day 2 | |
| #870 | HackermanPetrozavodsk Winter 2021 Day 2Interactive | |
| #871 | Interesting Scoring SystemsPetrozavodsk Winter 2021 Day 2 | |
| #872 | Joyful NumbersPetrozavodsk Winter 2021 Day 2 | |
| #873 | Königsberg BridgesPetrozavodsk Winter 2021 Day 2 | |
| #874 | Long Grid CoveringPetrozavodsk Winter 2021 Day 2 | |
| #875 | Arrange The PiranhasPetrozavodsk Winter 2021 Day 3BAPC 2020 | |
| #876 | Big BrotherPetrozavodsk Winter 2021 Day 3NCPC 2020 | |
| #877 | Company At DangerPetrozavodsk Winter 2021 Day 3BAPC 2020 | |
| #878 | Dams in DistressPetrozavodsk Winter 2021 Day 3NCPC 2020 | |
| #879 | Exhaustive ExperimentPetrozavodsk Winter 2021 Day 3NCPC 2020 | |
| #880 | Film CriticsPetrozavodsk Winter 2021 Day 3NCPC 2020 | |
| #881 | Gig CombinatoricsPetrozavodsk Winter 2021 Day 3NCPC 2020 | |
| #882 | Hiring and FiringPetrozavodsk Winter 2021 Day 3NCPC 2020 | |
| #883 | Infection EstimationPetrozavodsk Winter 2021 Day 3NCPC 2020Interactive | |
| #884 | Joining Treasure HuntPetrozavodsk Winter 2021 Day 3 | |
| #885 | Keep Calm And Carry OffPetrozavodsk Winter 2021 Day 3NCPC 2020 | |
| #886 | LanguagesPetrozavodsk Winter 2021 Day 3NCPC 2020 | |
| #887 | Final ExamPetrozavodsk Winter 2021 Day 4 | |
| #888 | Travel around ChinaPetrozavodsk Winter 2021 Day 4 | |
| #889 | WanderingPetrozavodsk Winter 2021 Day 4 | |
| #890 | InsectsPetrozavodsk Winter 2021 Day 4 | |
| #891 | Minimum Spanning TreePetrozavodsk Winter 2021 Day 4 | |
| #892 | Minimal CutPetrozavodsk Winter 2021 Day 4 | |
| #893 | RevenuePetrozavodsk Winter 2021 Day 4 | |
| #894 | Longest Loose SegmentPetrozavodsk Winter 2021 Day 4 | |
| #895 | ColorPetrozavodsk Winter 2021 Day 4 | |
| #896 | HorsesPetrozavodsk Winter 2021 Day 4 | |
| #897 | 基本子串字典 | |
| #898 | 二分图最大匹配 | |
| #899 | 一般图最大匹配 | |