摘要:
C. Valera and ElectionsThe city Valera lives in is going to hold elections to the city Parliament.The city hasndistricts andn - 1bidirecti... 阅读全文
摘要:
C. Misha and ForestLet's define a forest as a non-directed acyclic graph (also without loops and parallel edges). One day Misha played... 阅读全文