[luogu2982][USACO10FEB]慢下来Slowing down(树状数组+dfs序)
题目描述EverydayeachofFarmerJohn'sN(12#include3#include4typedefstruct{5intto,nxt;6}edge;7edgegra[200010];8inthead[100010],num=0;9intbeg[100010],end[100010],cnt=0;10intbit[100010],n;11inlineintadd(intfrm,i