A1022 Digital Library [map]

思路：根据书本信息查出所有的与之相关的书本编号，用map<string,set> 存 开五个容器存不同信息 根据不同的查询种类 利用关键字查询。
注意事项：
参数传引用比传值更快

#include<vector>
#include<iostream>
#include<algorithm>
#include<unordered_map>
#include<set>
#include<map>
#include<cstring>
#include<string>
using namespace std;
map<string, set<int> >title, author, key, pub, year;
void query(map<string, set<int>>&mp, string& str)
{
	if (mp.find(str) == mp.end())
		printf("Not Found
");
	else
	{
		for(set<int>::iterator it=mp[str].begin();it!=mp[str].end();it++)
            printf("%07d
",*it);
	}
}
int main()
{
	int n, m, id, type;
	string ctitle, cauthor, ckey, cpub, cyear;
	scanf("%d", &n);
	for (int i = 0; i < n; i++)
	{
		scanf("%d", &id);
		char c = getchar();
		getline(cin, ctitle);
		title[ctitle].insert(id);
		getline(cin, cauthor);
		author[cauthor].insert(id);
		while (cin >> ckey)
		{
			key[ckey].insert(id);
			c = getchar();
			if (c == '
') break;
		}
		getline(cin, cpub);
		pub[cpub].insert(id);
		getline(cin, cyear);
		year[cyear].insert(id);
	}
	string temp;
	scanf("%d", &m);
	for (int i = 0; i < m; i++)
	{
		scanf("%d: ", &type);
		getline(cin, temp);
		cout << type << ": " << temp << endl;
		if (type == 1) query(title, temp);
		else if (type == 2) query(author, temp);
		else if (type == 3) query(key, temp);
		else if (type == 4) query(pub, temp);
		else query(year, temp);
	}
	return 0;
}