填空题
Wired wire
发布于 2022-03-03 17:21:38
P company has a huge data center with n servers. There are n - 1 lines
between these servers. If two servers are connected by a wire, data can
only be sent from one server to another, but not vise versa. Without
considering the direction of data transmission, one server can reach any
other servers, which means that all servers are connected. The engineer
wants to select a central server which needs to send data to all other
servers. To achieve this goal, the direction of some wires should be
changed. The engineer is very lazy and he wants to select the server
which can result in the least operations on wires.
输入描述：
The first line contains an integer n, (2 <= n <= 100000) - the number of servers. Servers are numbered from 1 to n. Next n - 1 lines contain descriptions of the wire, one wire per line. A wire is described by two integers a, b(1 <= a, b <= n) - the number of the servers connected by the wire. The direction of data transmission is from a to b.输入样例：
4
3 1
4 2
3 4 输出描述：
The first line prints the minimum number that the engineer should change. In the second line print all possible central servers. If there are multiple servers, print servers in the increasing order.输出样例
0
3
关注者
0
被浏览
26
