2024-07-06Nanami and the Constructive Problem线段树优化建图一般用动态开点线段树实现建立对称的入树和出树点击查看代码#include<bits/stdc++.h>usingnamespacestd;vector<int>a[600005];intc[100005],cnt,tot,sum,id[600005],dfn[600005],low[600005],val[100005],n,m;stack<int>s;boolv[600005],h[600005