树的直径

inline void dfs(int u, int f, int & tar)
{
	int v;
	for(int e = hd[u]; e; e = nt[e])
	    if((v = to[e]) ^ f)
	    {
	    	dis[v] = dis[u] + w[e];
	    	if(dis[v] > dis[tar]) tar = v;
	    	dfs(v, u, tar);
		}
}

主函数里：

dfs(1, 0, p); 
dis[p] = 0;
dfs(p, 0, q);

标签：tar,int,void,dfs,inline,直径,dis
来源： https://www.cnblogs.com/fakeryu/p/16410726.html