hdu 1425 sort

sort

Time Limit: 6000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 16968    Accepted Submission(s): 4977

Problem Description

给你n个整数，请按从大到小的顺序输出其中前m大的数。

 

Input

每组测试数据有两行，第一行有两个数n,m(0<n,m<1000000)，第二行包含n个各不相同，且都处于区间[-500000,500000]的整数。

 

Output

对每组测试数据按从大到小的顺序输出前m大的数。

 

Sample Input

5 3 3 -35 92 213 -644

 

Sample Output

213 92 3

 

//哈希表，用空间换时间;用c++做时会超时;
#include<iostream>
#include<cstring>
//#include<cstdio>
using namespace std;

int a[1000001];	
int max=-1;

int main()
{
	int n,m,b,i;

	while(cin>>n>>m)
	{
		i=0;
		memset(a,0,sizeof(a));
		while(i<n)
		{
			cin>>b;
			i++;
			if(b>max)
			{
				max=b;
			}
			a[500000+b]=1;
		}
		i=max+500000;
		while(i)
		{
			if(a[i])
			{
				m--;
				cout<<i-500000;
				cout<<" ";
			}
			if(m==0) break;
			i--;
		}
		cout<<endl;
	}
	return 0;
}


/*#include<cstdio>

#include<iostream>

#include<algorithm>

#include<cmath>

#include<cstring>

using namespace std;

 

int num[1000005];

 

 

int main()

{

int n,m;


while(scanf("%d%d",&n,&m)==2)

{

memset(num,0,sizeof(num));

int i;

for(i=0;i<n;i++)

{

int temp;

scanf("%d",&temp);

num[temp+500000]++;

}

i=1000002;

bool yes=false;

while(m)

{

while(num[i])

{

if(yes) printf(" ");

printf("%d",i-500000);

yes=true;

num[i]--;

m--;

}

i--;

}


printf("\n");

}

 


return 0;

}
*/