- Time limit: 1.00 s
- Memory limit: 512 MB
Given a tree of n nodes, your task is to find a centroid, i.e., a node such that when it is appointed the root of the tree, each subtree has at most \lfloor n/2 \rfloor nodes.
The first input line contains an integer n: the number of nodes. The nodes are numbered 1,2,…,n.
Then there are n-1 lines describing the edges. Each line contains two integers a and b: there is an edge between nodes a and b.
Print one integer: a centroid node. If there are several possibilities, you can choose any of them.
- 1 \le n \le 2 \cdot 10^5
- 1 \le a,b \le n
5 1 2 2 3 3 4 3 5