4898 - 树形动态：树的重心（质心）

Consider a tree T with N (1 <= N <= 20,000) nodes numbered 1...N. Deleting any node from the tree yields a forest: a collection of one or more trees. Define the balance of a node to be the size of the largest tree in the forest T created by deleting that node from T. For example, consider the tree: 大致意思： 给定一棵树,求树的重心的编号以及重心删除后得到的最大子树的节点个数size,如果size相同就选取编号最小的

The first line of input contains a single integer t (1 <= t <= 20), the number of test cases. The first line of each test case contains an integer N (1 <= N <= 20,000), the number of congruence. The next N-1 lines each contains two space-separated node numbers that are the endpoints of an edge in the tree. No edge will be listed twice, and all edges will be listed.

For each test case, print a line containing two integers, the number of the node with minimum balance and the balance of that node.