ACM思维题训练集合 You are given two integers n and d. You need to construct a rooted binary tree consisting of n vertices with a root at the vertex 1 and the sum of d...

Now Fox Ciel becomes a commander of Tree Land. Tree Land, like its name said, has n cities connected by n - 1 undirected roads, and for any two cities there alw...

After getting AC after 13 Time Limit Exceeded verdicts on a geometry problem, Kuroni went to an Italian restaurant to celebrate this holy achievement. Unfortuna...

2.对于矩阵D，D[i][j]当 i!=j 时，是一条边，对于一条边而言无度可言为0，当i==j时表示一点，代表点i的度。

在postgresql11之前，为表增加一个包含非空默认值的字段，将会导致表重写，为每一行添加该字段，并填充默认值。如果该表在增加字段前非常大，那么将会非常耗时。...

Ramesses knows a lot about problems involving trees (undirected connected graphs without cycles)!

Mishka is decorating the Christmas tree. He has got three garlands, and all of them will be put on the tree. After that Mishka will switch these garlands on.

语法格式：mkdir 【option】【directory】 mkdir [选项] [目录] 注意：mkdir 命令以及后面的选项和目录，每个元之间都要至少要有一个空格 参数选项：-p，-m

1.基本介绍os.walk()：游走/漫步函数返回的是一个迭代器扫描某个指定目录下所包含的子目录和文件2.基本使用假设文件夹data有如下的目录结构(cmd 命令：tree /f)2.1...

You have unweighted tree of nn vertices. You have to assign a positive weight to each edge so that the following condition would hold: