OIsolutionmathcombinatoricsOGFluogu2025-05-21十二重计数法READ MORE +OIsolutionmathcodeforcesinteractiveconstructivenumber-theoryAd-hoc2025-05-20CF2109C (Div. 2) Hacking NumbersREAD MORE +OIsolutionnumber-theorysievepowerful-numberproject-euler2025-05-19PE484 Arithmetic DerivativePassword requiredREAD MORE +OIsolutionsortcodeforces2025-05-19CF2101B (Div. 1) Quartet SwappingREAD MORE +4current: 2total: 55∧