题目：https://pintia.cn/problem-sets/994805342720868352/problems/994805480801550336

这题应该算是最复杂的容器题之一了，用的是map >，实现了图书检索的效果
感觉不太会出这种题，对着算法笔记打了一遍代码理解了一下
注意一下第48、49行

代码

  1. #include<algorithm>
  2. #include<iostream>
  3. #include<vector>
  4. #include<cstdio>
  5. #include<map>
  6. #include<set>
  7. #include<string>
  8. using namespace std;
  10. map<string, set<int> > mpTitle, mpAuthor, myKey, mpPub, mpYear;
  12. void query(map<string, set<int> > &mp, string &str){
  13.     if(mp.find(str) == mp.end()){//没找到关键词
  14.         printf("Not Found\n");
  15.     } else {
  16.         for(auto it = mp[str].begin(); it != mp[str].end(); it++){
  17.             printf("%07d\n", *it);
  18.         }
  19.     }
  20. }
  22. int main(){
  23.     int n, m, type;
  24.     string title, author, key, pub, year;
  25.     scanf("%d", &n);
  26.     for(int i = 0; i < n; i++){
  27.         int tempid;
  28.         scanf("%d", &tempid);
  29.         char c = getchar();//吸收换行符
  30.         getline(cin, title);
  31.         mpTitle[title].insert(tempid);
  32.         getline(cin, author);
  33.         mpAuthor[author].insert(tempid);
  34.         while(cin >> key){
  35.             myKey[key].insert(tempid);
  36.             c = getchar();
  37.             if(c == '\n') break;
  38.         }
  39.         getline(cin, pub);
  40.         mpPub[pub].insert(tempid);
  41.         getline(cin, year);
  42.         mpYear[year].insert(tempid);
  43.     }
  44.     string temp;
  45.     scanf("%d",&m);
  46.     for(int i = 0; i < m; i++){
  47.         scanf("%d: ",&type);
  48.         getline(cin, temp);
  49.         cout<<type<<": "<<temp<<endl;
  50.         if(type == 1) query(mpTitle, temp);
  51.         else if(type == 2) query(mpAuthor, temp);
  52.         else if(type == 3) query(myKey, temp);
  53.         else if(type == 4) query(mpPub,temp);
  54.         else if(type ==5) query(mpYear, temp);
  55.     }
  56.     return 0;
  57. }