string 映射到一个 int型的集合,巧妙
#include<iostream>
#include<map>
#include<string>
#include<set>
using namespace std;
map<string,set<int>> mptitle,mpauthor,mpkey,mppub,mpyear;
void query(map<string,set<int>>& mp, string& str){
if(mp.find(str)==mp.end()) printf("Not Found\n");
else{
for(set<int>::iterator it=mp[str].begin();it!=mp[str].end();it++){
printf("%07d\n",*it);
}
}
}
int main(){
int n;
scanf("%d",&n);
int id;
string title,author,key,pub,year;
for(int i=0;i<n;i++){
scanf("%d",&id);
char c = getchar();
getline(cin,title);
mptitle[title].insert(id);
getline(cin,author);
mpauthor[author].insert(id);
while(cin>>key){
mpkey[key].insert(id);
c=getchar();
if(c=='\n') break;
}
getline(cin,pub);
mppub[pub].insert(id);
getline(cin,year);
mpyear[year].insert(id);
}
int m;
scanf("%d",&m);
int type;
string temp;
for(int i=0;i<m;i++){
scanf("%d: ",&type);
getline(cin,temp);
cout<< type << ": " << temp << endl;
if(type==1) query(mptitle,temp);
else if(type==2) query(mpauthor,temp);
else if(type==3) query(mpkey,temp);
else if(type==4) query(mppub,temp);
else query(mpyear,temp);
}
return 0;
}