HDU-6886 Tic-Tac-Toe-Nim(2020HDU多校第十场T10)
[HDU-6883] Coin Game(2020HDU多校第十场T7)
[[HDU-6791] 2020HDU多校第三场T1](回文自动机)
[HDU-6848] Expectation (2020多校7T5) (Dp)
[HDU-6847] Decision (2020多校7T4) (类欧几里得问题)
[HDU-6854] Kcats (2020多校7 T11) (笛卡尔树+区间Dp)
[HDU-6834] Yukikaze and Smooth Numbers
[HDU - 6833] a Very Easy Math Problem (莫比乌斯反演)
HDU-6801 2020HDU多校第三场T11 (生成函数)
HDU-5608