hiho一下 第十五周 最近公共祖先·二 - 更新一下tarjan离线LCA模板

                 题意:

                          裸LCA

                 题解:

                          tarjan离线解LCA模板...

Program:

#include<iostream>#include<stdio.h>#include<math.h>#include<string.h> #include<string>#include<queue>#include<map>#include<algorithm>#define MAXN 100005#define ll long long#define oo 1e+10#define eps 1e-10using namespace std; struct node{      int u,v,id,next;}edge[MAXN],Qedge[MAXN<<1];map<string,int> H;int En,Vn,_next[MAXN],D[MAXN],father[MAXN];int Qen,Qnext[MAXN],ans[MAXN];bool visited[MAXN];char st[MAXN];string s,name[MAXN];int getdata(){      scanf("%s",st),s=st;      if (H.find(s)==H.end()) H[s]=++Vn,name[Vn]=s;      return H[s];}void addedgeE(int u,int v){      edge[++En].next=_next[u],_next[u]=En;      edge[En].v=v;}void addedgeQ(int u,int v,int id){      Qedge[++Qen].next=Qnext[u],Qnext[u]=Qen;      Qedge[Qen].v=v,Qedge[Qen].id=id;}int getfather(int u){      if (father[u]==u) return u;      return father[u]=getfather(father[u]);}void tarjan(int u){      int k,v,id;      father[u]=u;      visited[u]=true;      for (k=Qnext[u];k;k=Qedge[k].next)      {               v=Qedge[k].v,id=Qedge[k].id;               if (!visited[v]) continue;               ans[id]=getfather(v);      }      for (k=_next[u];k;k=edge[k].next)      {               v=edge[k].v;                tarjan(v);               father[v]=u;      }}   int main(){             int n,Q,i,u,v;      string s;        scanf("%d",&n),Vn=0,H.clear();      memset(_next,0,sizeof(_next)),En=0;      memset(D,0,sizeof(D));      while (n--)      {              u=getdata(),v=getdata();              D[v]++;              addedgeE(u,v);      }      scanf("%d",&Q);      memset(Qnext,0,sizeof(Qnext)),Qen=0;      for (i=1;i<=Q;i++)      {              u=getdata(),v=getdata();              addedgeQ(u,v,i),addedgeQ(v,u,i);      }      memset(visited,0,sizeof(visited));      tarjan(1);      for (i=1;i<=Q;i++) puts(name[ans[i]].c_str());      return 0;}