1 |
P1 - You Are Given a Tree |
Codeforces |
Codeforces Round #507 (Div. 1, based on Olympiad of Metropolises) |

2 |
P2 - Region Separation |
Codeforces |
Codeforces Round #511 (Div. 1) & Codeforces Round #511 (Div. 2) |

3 |
P3 - Triple Flips |
Codeforces |
Technocup 2019 - Elimination Round 2 |

4 |
P4 - Sergey's problem |
Codeforces |
Codeforces Round #503 (by SIS, Div. 1) & Codeforces Round #503 (by SIS, Div. 2) |

5 |
P5 - Concise and clear |
Codeforces |
Codeforces Round #491 (Div. 2) |

6 |
P6 - Cowmpany Cowmpensation |
Codeforces |
Codeforces Round #492 (Div. 1) [Thanks, uDebug!] |

7 |
P7 - Sky Full of Stars |
Codeforces |
Codeforces Round #493 (Div. 1) & Codeforces Round #493 (Div. 2) |

8 |
P8 - Cycles in product |
Codeforces |
Codeforces Round #493 (Div. 1) |

9 |
P9 - Sonya and Bitwise OR |
Codeforces |
Codeforces Round #495 (Div. 2) |

10 |
P10 - Store |
Codeforces |
Codeforces Round #499 (Div. 1) |

11 |
P11 - AB-Strings |
Codeforces |
Codeforces Round #500 (Div. 1) [based on EJOI] & Codeforces Round #500 (Div. 2) [based on EJOI] |

12 |
P12 - Kuro and Topological Parity |
Codeforces |
Codeforces Round #482 (Div. 2) |