2016-2017 CT S03E05: Codeforces Trainings Season 3 Episode 5 (2016 Stanford Local Programming Contest, Extended) E

学弟写的，以后再补

#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <cstring>
#include <map>
#include <vector>
using namespace std;
map<string,int>v,ans;
vector<int>que[40020];
string b[40020];
int pre[40020],vis[40020],a[40020],c[40020],d[40020];
 
void dfs(int x){
    if(c[x]==1) ans[b[x]]=1;
    vis[x]=1;
    for(int i=0;i<que[x].size();i++){
        int y=que[x][i];
        if(!vis[y]){
            dfs(y);
        }
    }
}
 
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0),cout.tie(0);
    int T,n,m,k,cnt,p;
    cin>>T;
    string s,s1; 
    while(T--){
        memset(vis,0,sizeof(vis));
        memset(c,0,sizeof(c));
        cnt=0,p=1;
        cin>>n>>m>>k;
        for(int i=0;i<n;i++){
            cin>>s;
            if(!v[s]){
                b[p]=s;
                v[s]=p++;
            }
            d[i]=v[s];
        }
        for(int i=0;i<m;i++){
            cin>>s;
            if(!v[s]){
                b[p]=s;
                v[s]=p++;
            }
            c[v[s]]=1;
        }
        while(k--){
            cin>>s>>s1;
            if(!v[s]) {
                b[p]=s;
                v[s]=p++;
            }
            if(!v[s1]) {
                b[p]=s1;
                v[s1]=p++;
            }
            que[v[s]].push_back(v[s1]);
        }
        for(int i=0;i<n;i++){
            if(!vis[d[i]]){
                dfs(d[i]);
            }
        }
        int f=1;
        for(auto it : ans){
            if(f) f=0,cout<<(it.first);
            else cout<<" "<<(it.first);
        }
        if(!f) cout<<endl;
        v.clear(),ans.clear();
        for(int i=0;i<40020;i++) que[i].clear();
    }
}