我有两个数组:
String [] ids= new String [5];
String [] points= new String [5];
String one="a,b,c,d,e";
//or
String one="nepal,japan,finland ,brazil,spain";
String two="100,500,200,400,300";
ids= one.split(",");
points= two.split(",");
现在我想按降序对点
进行排序。
500,400,300,200,100 with respective ids b,d,e,c,a
我该怎么做。
但是我尝试按降序排列,这是可以的,但是如何使用相应的 id 来排序 id。
Arrays.sort(points, Collections.reverseOrder());
Arrays.toString(points);
或
Arrays.sort(points);
如果我做同样的事情 ids 也是降序的。但没有输出。
已编辑:
如果我更换了
a、b、c、d、e 致国家名称或时间的信件。
String one="a,b,c,d,e";
// or
String countries = "nepal,japan,finland,brazil,spain";
// or
String time="0:10,1:25,4:00,2:10,0:55";
最佳答案
您可以定义自己的比较器
,如下所示:
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
public class CustomArrayComparator implements Comparator<String>
{
private String[] pointsArray;
private Map<String, Integer> idsMap;
public CustomArrayComparator(String[] pointsArray, String[] countriesArray)
{
this.pointsArray = pointsArray;
idsMap = new HashMap<String, Integer>();
for(int i = 0; i < pointsArray.length; i++) idsMap.put(countriesArray[i], i);
}
@Override
public int compare(String s1, String s2)
{
return pointsArray[idsMap.get(s2)].compareTo(pointsArray[idsMap.get(s1)]);
}
}
这是主要内容:
String[] points = {"100", "500", "200", "400", "300"};
String[] countries = {"nepal", "japan", "finland", "brazil", "spain"};
CustomArrayComparator comparator = new CustomArrayComparator(points, countries);
Arrays.sort(countries, comparator);
Arrays.sort(points, Collections.reverseOrder());
System.out.println(Arrays.toString(points));
System.out.println(Arrays.toString(countries));
输出:
[500, 400, 300, 200, 100]
[japan, brazil, spain, finland, nepal]
编辑:
作为通用类,这里是具有通用实现的同一个类:
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
public class CustomArrayComparator<T extends Comparable<T>, E> implements Comparator<T>
{
private T[] mainArray;
private Map<E, Integer> indexesMap;
public CustomArrayComparator(T[] mainArray, E[] associatedArray)
{
this.mainArray = mainArray;
indexesMap = new HashMap<E, Integer>();
for(int i = 0; i < mainArray.length; i++)
{
indexesMap.put(associatedArray[i], i);
}
}
@Override
public int compare(T t1, T t2)
{
return mainArray[indexesMap.get(t2)].compareTo(mainArray[indexesMap.get(t1)]);
}
}
主要:
String[] points = {"100", "500", "200", "400", "300"};
String[] countries = {"nepal", "japan", "finland", "brazil", "spain"};
Comparator<String> comparator = new CustomArrayComparator<String, String>(points, countries);
Arrays.sort(countries, comparator);
Arrays.sort(points, Collections.reverseOrder());
System.out.println(Arrays.toString(points));
System.out.println(Arrays.toString(countries));
输出:
[500, 400, 300, 200, 100]
[japan, brazil, spain, finland, nepal]
关于java - 如何使用相应的数组 ID 或值对数组进行排序?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/8775807/