爱种树的码农

摘要： H. HighwayIn ICPCCamp there were n towns conveniently numbered with 1,2,...,n connected with (n−1) roads. Thei-th road connecting towns a i and b i ha 阅读全文

摘要： E. Partial SumBobo has a integer sequence a 1 ,a 2 ,...,a n of length n. Each time, he selects two ends 0 ≤ l < r ≤ n andadd |∑ rj=l+1 a j | − C into 阅读全文