C语言解答

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#include<string.h>
#include<time.h>
 
int num[1000005];
 
int hash( int x )
{
    return x+ 500000;
}
 
int back( int x )
{
    return x- 500000;
}
 
int main(  )
{
    int N, M, cnt, min, max;
    while( ~scanf( "%d%d", &N, &M ) )
    {
        cnt= 0;
        min= 0x7fffffff;
        max= 0x7fffffff+ 1;
        memset( num, 0, sizeof( num ) );
        while( N-- )
        {
            int c;
            scanf( "%d", &c );
            if( min> hash( c ) )
            {
                min= hash( c );
            }
            if( max< hash( c ) )
            {
                max= hash( c );
            }
            num[ hash( c ) ]= 1;
        }
        for( int i= max; i>= min; --i )
        {
            if( num[i] )
            {
                cnt++;
                printf( "%d", back( i ) );
                if( cnt< M )
                {
                    printf( " " );
                }
                if( cnt== M )
                {
                    break;
                }
            }
        }
        puts( "" );
    }
} 

C++解答

#include <iostream>
#include <string.h>
#include <cstdio>
using namespace std;
const int N=1000005;
int num[N];
int partition(int low,int high){
	int i=low,j=high,key=num[low];
	while(i<j){
	  while(i<j&&num[j]>key) --j;
	  int t=num[i]; num[i]=num[j];num[j]=t;
	  while(i<j&&num[i]<key)  ++i;
	  t=num[i];num[i]=num[j];num[j]=t;
	}
	return i;
}
void quick_sort(int low,int high){
  if(low<high){
    int x=partition(low,high);
    quick_sort(low,x-1);
    quick_sort(x+1,high);
  }
}
int main(){
  int n,m;
  while(~scanf("%d%d",&n,&m)){
    for(int i=0;i<n;++i)
		scanf("%d",&num[i]);
	quick_sort(0,n-1);
	for(int i=n-1;i>n-m;--i)
		printf("%d ",num[i]);
	printf("%d",num[n-m]);
	printf("\n");
  }
  return 0;
}

Java解答

import java.util.Comparator;
import java.util.PriorityQueue;
import java.util.Queue;
import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * User: Worshiper
 * Date: 13-10-28
 * Time: 下午10:39
 */
public class Main{
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNext()) {
            int n = in.nextInt();
            int m = in.nextInt();
            Queue<Integer> queue = new PriorityQueue<Integer>(16, new Comparator<Integer>() {
                @Override
                public int compare(Integer o1, Integer o2) {

                    return o1 > o2 ? -1 : 1;
                }
            });
            for (int i = 0; i < n; i++) {
                queue.add(in.nextInt());
            }

            for (int i = 0; i < m - 1; i++) {
                System.out.print(queue.poll() + " ");
            }

            System.out.println(queue.poll());
        }
    }
}

Python解答

import sys
x = []
for line in sys.stdin:
  x += line.strip('\n').split()
x = [int(i) for i in x]
while x:
  n,m = x[0], x[1]
  s = x[2:n+2]
  ss = sorted(s,reverse=True)[:m]
  print ' '.join(str(x) for x in ss)
  x = x[2+n:]