1 |
P1 - Text Editor |
Codeforces |
Codeforces Round #154 (Div. 2) |

2 |
P2 - Jon and Orbs |
Codeforces |
Divide by Zero 2017 and Codeforces Round #399 (Div. 1 + Div. 2, combined) |

3 |
P3 - Magic Trick |
Codeforces |
MemSQL Start[c]UP 2.0 - Round 1 |

4 |
P4 - Something with XOR Queries |
Codeforces |
Technocup 2018 - Elimination Round 2 |

5 |
P5 - Smart Cheater |
Codeforces |
Codeforces Round #107 (Div. 1) & Codeforces Round #107 (Div. 2) |

6 |
P6 - Castle |
Codeforces |
Codeforces Beta Round #79 (Div. 1 Only) |

7 |
P7 - Roman and Numbers |
Codeforces |
Codeforces Round #235 (Div. 2) |

8 |
P8 - GCD Counting |
Codeforces |
Educational Codeforces Round 45 (Rated for Div. 2) |

9 |
P9 - Digital Root |
Codeforces |
Codeforces Beta Round #10 |

10 |
P10 - Unusual Sequences |
Codeforces |
Codeforces Round #450 (Div. 2) |

11 |
P11 - Tractor College |
Codeforces |
Codeforces Round #126 (Div. 2) |

12 |
P12 - Notepad |
Codeforces |
Codeforces Beta Round #17 |

13 |
P13 - Vika and Segments |
Codeforces |
Codeforces Round #337 (Div. 2) |

14 |
P14 - Restore Cube |
Codeforces |
Codeforces Round #265 (Div. 1) |

15 |
P15 - Mirror Box |
Codeforces |
Bayan 2012-2013 Elimination Round (ACM ICPC Rules, English statements) |

16 |
P16 - Rectangle Puzzle |
Codeforces |
Codeforces Round #172 (Div. 1) & Codeforces Round #172 (Div. 2) |

17 |
P17 - Congruence Equation |
Codeforces |
Codeforces Round #460 (Div. 2) |

18 |
P18 - Anniversary |
Codeforces |
Codeforces Round #140 (Div. 1) & Codeforces Round #140 (Div. 2) |

19 |
P19 - Xor-sequences |
Codeforces |
Educational Codeforces Round 14 |

20 |
P20 - Vanya and Brackets |
Codeforces |
Codeforces Round #308 (Div. 2) |

21 |
P21 - Sum of Medians |
Codeforces |
Yandex.Algorithm 2011 Round 1 |

22 |
P22 - Sandy and Nuts |
Codeforces |
Codeforces Round #332 (Div. 2) |

23 |
P23 - T-decomposition |
Codeforces |
Codeforces Round #147 (Div. 2) |