Question

好的，所以我在这里有点不知所措，但是这里有。因此我需要在打印出来时对阵列奖章进行排序。首先，我需要按照添加到索引[0]的金牌排序，在索引[1]中的银牌之后排名第二，在索引[2]中排在铜牌之后排名第三，如果团队被绑定则排在最后，他们按球队名称排序。我是否需要在另一个班级中调用排序方法，跟踪其中一个并进行排序并与其他团队进行比较，如果他们最好先打印出来？

如何比较一个类的数组中的整数？

当用户输入某个命令时，将打印出包含其结果的团队列表。

截至目前，它看起来像这样：

1st 2nd 3rd  Team Name
0   0     0      North Korea
3   1     1      America
5   0     2      France
2   1     3      Germany

我想说：

1st 2nd 3rd  Team Name
5   0     2  France
3   1     1  America
2   1     3  Germany
0   0     0  North Korea

import java.util.ArrayList;
import java.util.Arrays;

public class Team {
    private String teamName;
    private ArrayList<Participant> participantList = new ArrayList<Participant>();
    private int[] medalList = new int[3];

    public Team(String teamName) {
        this.teamName = teamName;
    }

    public String getTeamName() {
        return teamName;
    }

    public void addParticipant(Participant participant) {
        participantList.add(participant);
    }

    public void removeFromTeam(int participantNr){
        for(int i = 0; i < participantList.size(); i++){
            if(participantList.get(i).getParticipantNr() == participantNr){
                participantList.remove(i);
            }
        }
    }

    public void printOutParticipant() {
        for(int i = 0; i < participantList.size(); i++){
            System.out.println(participantList.get(i).getName() + " " + participantList.get(i).getLastName());
        }
    }

    public boolean isEmpty() {
        boolean empty = false;
        if (participantList.size() == 0) {
            empty = true;
            return empty;
        }
        return empty;
    }

    public void emptyMedalList(){
        Arrays.fill(medalList, 0);
    }

    public void recieveMedals(int medal) {
        if(medal == 1){
            int gold = 0;
            gold = medalList[0];
            medalList[0] = ++gold;
        } else if (medal == 2){
            int silver = 0;
            silver = medalList[1];
            medalList[1] = ++silver;
        } else if (medal == 3){
            int bronze = 0;
            bronze = medalList[2];
            medalList[2] = ++bronze;
        }
    }

    public void printMedals(){
        System.out.println(medalList[0] + "   " + medalList[1] + "   " + medalList[2] + "   " + teamName);
    }

   public int compareTo(Team team) {
    int goldDif = Integer.compare(team.medalList[0], this.medalList[0]);
    if (goldDif != 0)
            return goldDif;
    int silverDif = Integer.compare(team.medalList[1], this.medalList[1]);
    if (silverDif != 0)
        return silverDif;
    int bronzeDif = Integer.compare(team.medalList[2], this.medalList[2]);
    if (bronzeDif != 0)
        return bronzeDif;
    return this.getTeamName().compareTo(team.getTeamName());
}

    public String toString() {
        return teamName;
    }

}

Answer 1

使您的团队课程具有可比性

public class Team implements Comparable<Team> {

并添加比较方法

@Override
public int compareTo(final Team other) {
    for (int i = 0; i < 3; i++) {
        final int compareMedals = Integer.compare(medalList[i], other.medalList[i])
        if (compareMedals != 0) {
            return compareMedals;
        }
    }
    return teamName.compareTo(other.teamName);
}

这将首先检查金牌，然后如果金牌数量相等则获得银牌，并使用团队名称比较作为最后的手段。然后，您可以使用

对Team s的集合进行排序

final List<Team> teams = new ArrayList<>();
...
Collections.sort(teams);

修改

或者如果您喜欢Java 8风格，您也可以编写比较方法，如

@Override public int compareTo(final Team other) { return Stream.of(0, 1, 2) .map(i -> Integer.compare(medalList[i], other.medalList[i])) .filter(i -> i != 0) .findFirst() .orElse(teamName.compareTo(other.teamName)); }

比较Integer，类实例的数组

1 个答案: