Timus 1446. Sorting Hat 分类问题

At the start of each school year, a very important event happens at Hogwarts. Each of the first-year wizards and witches is assigned to one of the four Hogwarts houses. The bravest children are put
to Gryffindor, the cleverest are put to Ravenclaw, the most hard-working go to Hufflepuff, and Slytherin becomes home to the most ambitious. The assignment is carried out in the Great Hall of Hogwarts castle in the following way: when the name of a first-year
student is called, he or she comes out to the center of the Hall and puts on the famous Sorting Hat. The Hat estimates the situation in the head of the young wizard or witch and cries out the name of the house to which the student is assigned. A special elf
writes down the Hat's decisions. After the sorting, the elf must quickly compile lists of students of each house. Members of the Society for the Promotion of Elfish Welfare beg you to help the elf in this hard work.

Input

The first line contains the number of first-year students N (1 ≤ N ≤ 1000). In the next 2N lines there are their names followed by houses in which the Sorting Hat placed them.
A student's name may contain lowercase and uppercase English letters, spaces and hyphens. Each name contains not more than 200 symbols.

Output

Output lists of students of each house in the following format. In the first line there is the name of the house, then a colon, and in the next lines there is the list of students, one in a line. The
lists must be given in the following order: Slytherin, Hufflepuff, Gryffindor, Ravenclaw. There must be empty lines between the lists. In each list, names must be given in the order in which they were called out during the sorting. It is guaranteed that each
list will contain at least one student.

Sample

input	output
7 Ivan Ivanov Gryffindor Mac Go Nagolo Hufflepuff Zlobeus Zlei Slytherin Um Bridge Slytherin Tatiana Henrihovna Grotter Ravenclaw Garry Potnyj Gryffindor Herr Mionag-Ranger Gryffindor	Slytherin: Zlobeus Zlei Um Bridge Hufflepuff: Mac Go Nagolo Gryffindor: Ivan Ivanov Garry Potnyj Herr Mionag-Ranger Ravenclaw: Tatiana Henrihovna Grotter

这是个利用map来分类的问题。

注意一下getline的运用，会把之前遗漏下来的换行符都继续读取的，所以记得要去掉之前有输入而又不使用getline读入的换行符。

利用一个数据结构：unordered_map<string, vector<string>>就能解决这个问题了

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

namespace{

	static const int HOUSES = 4;
	string houses[HOUSES] = {"Slytherin","Hufflepuff","Gryffindor","Ravenclaw"};

}

void SortingHat1446()
{
	int n = 0;
	cin>>n;	

	string name, houseName;
	cin.ignore();//注意：去掉这个dumb换行符

	unordered_map<string, vector<string> > umSVS;
	for (int i = 0; i < n; i++)
	{
		getline(cin, name);
		getline(cin, houseName);
		umSVS[houseName].push_back(name);
	}
	for (int i = 0; i < HOUSES; i++)
	{
		vector<string> tmp = umSVS[houses[i]];
		cout<<houses[i]<<":\n";
		for (int j = 0; j < (int)tmp.size(); j++)
		{
			cout<<tmp[j]<<endl;
		}
		cout<<endl;
	}
}
int main()
{
	SortingHat1446();
	return 0;
}