标签 ACPC 下的文章

Arab Collegiate Programming Contest 2015

题目链接：A. Christmas Treeconst int maxn = 2e6 + 10; vector<int> e[200005]; int dep[maxn],id[maxn],p[maxn],idx=0; void dfs(int x,int f){ dep[x]=dep[f]+1; id[x]=++idx; p[idx]=x; fo...