onlyblues

摘要： D. Absolute Beauty Kirill has two integer arrays $a_1,a_2,\ldots,a_n$ and $b_1,b_2,\ldots,b_n$ of length $n$. He defines the absolute beauty of the ar 阅读全文

摘要： G. Unusual Entertainment A tree is a connected graph without cycles. A permutation is an array consisting of $n$ distinct integers from $1$ to $n$ in 阅读全文