[PAT解题报告] Digital Library

#include <cstdio>
#include <map>
#include <string>
#include <cstring>
#include <sstream>
#include <set>

using namespace std;

map<string, set<string> > title, author,word, publisher, year;

char s[1000];

void make(map<string,set<string> > &a, const char *s) {
map<string,set<string> >::iterator t = a.find(s);
    if ((t == a.end()) || (t->second.empty())) {
        puts("Not Found");
    }
    else {
        for (set<string>::iterator it = t->second.begin(); it != t->second.end(); ++it) {
            puts(it->c_str());
        }
    }
}

int main() {
int n;
    scanf("%d",&n);
    for (gets(s);n;--n) {
        gets(s);
        string id = s;
        gets(s);
        title[s].insert(id);
        gets(s);
        author[s].insert(id);
        gets(s);
        istringstream in(s);
        string temp;
        while (in >> temp) {
            word[temp].insert(id);
        }
        gets(s);
        publisher[s].insert(id);
        gets(s);
        year[s].insert(id);
    }
    scanf("%d",&n);
    for (gets(s);n;--n) {
        gets(s);
        puts(s);
        switch(s[0]) {
        case '1':
            make(title, s + 3);
            break;
        case '2':
            make(author, s + 3);
            break;
        case '3':
            make(word, s + 3);
            break;
        case '4':
            make(publisher, s + 3);
            break;
        case '5':
            make(year, s + 3);
            break;
        }
    }
    return 0;
}