CodeForces - 659B Qualifying Contest （模拟）水

64bit IO Format: %I64d & %I64u

CodeForces - 659B

Qualifying Contest

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Description

Very soon Berland will hold a School Team Programming Olympiad. From each of the m Berland regions a team of two people is invited to participate in the olympiad. The qualifying contest to form teams was held and it was attended by n Berland students. There were at least two schoolboys participating from each of the m regions of Berland. The result of each of the participants of the qualifying competition is an integer score from 0 to 800

The team of each region is formed from two such members of the qualifying competition of the region, that none of them can be replaced by a schoolboy of the same region, not included in the team and who received a greater

Your task is, given the results of the qualifying competition, to identify the team from each region, or to announce that in this region its formation requires additional contests.

Input

The first line of the input contains two integers n and m (2 ≤ n ≤ 100 000, 1 ≤ m ≤ 10 000, n ≥ 2m) — the number of participants of the qualifying contest and the number of regions in Berland.

Next n lines contain the description of the participants of the qualifying contest in the following format: Surname (a string of length from 1 to 10 characters and consisting of large and small English letters), region number (integer from 1 to m) and the number of points scored by the participant (integer from 0 to 800, inclusive).

It is guaranteed that all surnames of all the participants are distinct and at least two people participated from each of the mregions. The surnames that only differ in letter cases, should be considered distinct.

Output

Print m lines. On the i-th line print the team of the i-th region — the surnames of the two team members in an arbitrary order, or a single character "?" (without the quotes) if you need to spend further qualifying contests in the region.

Sample Input

Input

5 2Ivanov 1 763Andreev 2 800Petrov 1 595Sidorov 1 790Semenov 2 503

Output

Sidorov IvanovAndreev Semenov

Input

5 2Ivanov 1 800Andreev 2 763Petrov 1 800Sidorov 1 800Semenov 2 503

Output

?Andreev Semenov

//题意：输入n,m,n表示有n个人，m表示这n个人来自m个不同的地区，接下来n行为n个人的个人信息，分别为名字，地区号，他的积分（积分越高，水平越高）。

现在每个地区要选出一个队伍去参见比赛，每个队伍有两个人组成，问这m个地区是否有确定的人选，有的话输出两个人的名字，如没有输出？。

Hait：样例二中地区1有三个大神，水平都是满级，但是不能确定让哪两个去，所以也是不确定的。

#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<iostream>
#define INF 0x3f3f3f3f
#define ull unsigned long long
#define ll long long
#define IN __int64
#define N 100010 
#define M 1000000007
using namespace std;
struct zz
{
	char name[15];
	int area;
	int score;
}p[N];
bool cmp(zz a,zz b)
{
	if(a.area==b.area)
		return a.score>b.score;
	return a.area<b.area;
}
struct ss
{
	char name1[15];
	char name2[15];
	int k;
}s[N];
int main()
{
	int t,n,m,i,j,k;
	while(scanf("%d%d",&n,&m)!=EOF)
	{
		for(i=0;i<n;i++)
			scanf("%s%d%d",p[i].name,&p[i].area,&p[i].score);
		sort(p,p+n,cmp);
		int flag=0;
		i=1;j=0;
		while(i<=m&&j<n)
		{
			if(p[j].area!=i)
			{
				j++;
				continue;
			}
			if(p[j].area==i)
			{
				if(p[j+1].area==i)
				{
					if(p[j+2].area==i)
					{
						if(p[j+2].score==p[j+1].score)
							flag=1;
					}
				}
				else
					flag=1;
			}
			if(flag)
				s[i].k=1;
			else
			{
				strcpy(s[i].name1,p[j].name);
				strcpy(s[i].name2,p[j+1].name);
			}
			i++;flag=0;
		}
		for(i=1;i<=m;i++)
		{
			if(s[i].k)
				printf("?\n");
			else
				printf("%s %s\n",s[i].name1,s[i].name2);
		}
	}
	return 0;
}