P4728-[HNOI2009]双递增序列 题目: 题目描述: 考虑一个长度为偶数 $n$ 的序列 $a_1, a_2, \dots, a_n$，我们称这个序列为好的，当且仅当存在 $a_1, a_2, \dots,

P3224-[HNOI2012]永无乡 题目: 题目描述: 永无乡包含 $n$ 座岛，编号从 $1$ 到 $n$ ，每座岛都有自己的独一无二的重要度，按照重要度可以将这 $n$

P5205-【模板】多项式开根 题目: 题目描述: 给定一个$n-1$次多项式$A(x)$，求一个在$\bmod\ x^n$意义下的多项式$B(x)

CF525D-Arthur and Walls 题目: 题目描述: Finally it is a day when Arthur has enough money for buying an apartment. He found a great option close to the center of the city with a nice price. Plan of the apartment found by Arthur looks like a rectangle $ n×m $ consisting of squares of size $ 1×1 $ . Each of

CF662B-Graph Coloring 题目: 题目描述: You are given an undirected graph that consists of $ n $ vertices and $ m $ edges. Initially, each edge is colored either red or blue. Each turn a player picks a single vertex and switches the color of all edges incident to it. That is, all red edges with an endpoint in this vertex change the color to

CF1120D-Power Tree 题目: 题目描述: You are given a rooted tree with $ n $ vertices, the root of the tree is the vertex $ 1 $ . Each vertex has some non-negative price. A leaf of the tree is a non-root vertex that has degree $ 1 $ . Arkady and Vasily play a strange game on the tree. The game consists of three