题解 | 生词篇章查询 | ump建立映射 ust去重

#include <iostream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
using namespace std;

int main(){
    ios::sync_with_stdio(false);cin.tie(nullptr);
    unordered_map<string,vector<int>> word2Docs;
    int N;cin>>N;
    for(int docId=1;docId<=N;++docId){
        unordered_set<string> uniqueWords;
        int L;cin>>L;
        while(L--){
            string word;cin>>word;
            uniqueWords.insert(word);
        }
        for(const auto& word:uniqueWords){
            word2Docs[word].push_back(docId);
        }
    }

    int M;cin>>M;
    while(M--){
        string query;cin>>query;
        auto it=word2Docs.find(query);
        if(it!=word2Docs.end()){
            const auto& docs=it->second;
            cout<<docs[0];
            for(int i=1;i<docs.size();++i) cout<<' '<<docs[i];
        }
        cout<<'\n';
    }

    return 0;
}