java - 如何修复我的排序方法以便我得到名称的字母顺序

Question

我正在尝试修复我的排序方法。我正在从 txt 文件中读取并尝试按字母顺序获取它们。

我不能使用类似的工具然后使用collections.sort()，因为我的老师不允许这样做。

//How I am trying to sort
public static void sortPlayers(ArrayList<BingoPlayer> players){
    BingoPlayer temp;
    int value = 0;
    for(int i = 0; i < players.size()-1; i++)
    {
        value = compareTo(players.get(i), players.get(i + 1));

        if(value < 0 || value == 0){
            //continue;
        }
        else if(value > 0){
            temp = players.get(i);
            players.set(i, players.get(i + 1));
            players.set(i + 1, temp);
        }
    }

}
 //How am I comparing. 
public static int compareTo(BingoPlayer player1, BingoPlayer player2){
    if(player1.firstName.compareTo(player2.firstName) < 0)
        return player1.firstName.compareTo((player2.firstName));
    else if(player1.firstName.compareTo(player2.firstName) > 0)
        return player1.firstName.compareTo((player2.firstName));
    else 
        if (player1.lastName.compareTo(player2.lastName) < 0)
            return player1.lastName.compareTo((player2.lastName));
        else if (player1.lastName.compareTo(player2.lastName) > 0)
            return player1.lastName.compareTo((player2.lastName));
            else 
                return 0;
}

这是我正在读取的txt文件:

50.00
10
James,Smith,50.0
Michael,Smith,50.0
Robert,Smith,50.0
Maria,Garcia,50.0
David,Smith,50.0
Maria,Rodriguez,50.0
Mary,Smith,50.0
Maria,Hernandez,50.0
Maria,Martinez,50.0
James,Johnson,50.0

Answer 1

您需要使用嵌套for循环进行排序

public static void sortPlayers(ArrayList<BingoPlayer> players){
    BingoPlayer temp;
    int value = 0;
    for(int i = 1; i <= players.size()-1; i++)
    {

        for(int j=i;j>0;j--){
            value = compareTo(players.get(j), players.get(j - 1));

            if(value < 0){
                temp = players.get(j);
                players.set(j, players.get(j - 1));
                players.set(j - 1, temp);
            }
        }
    }

}

我还稍微优化了您的比较功能:

public static int compareTo(BingoPlayer player1, BingoPlayer player2){
    if(player1.firstName.compareTo(player2.firstName) != 0)
        return player1.firstName.compareTo((player2.firstName));
    else 
        return player1.lastName.compareTo((player2.lastName));
}