找出我已经认识的玩家

Question

我有以下数据结构：

public class Match
{

    public List<Player> Participants;

}

public class Player
{

    public string Name;

}

现在我得到了以下示例数据：

Match 1
 - PlayerA
 - PlayerB
 - PlayerC

Match 2
 - PlayerA
 - PlayerB
 - PlayerD
 - PlayerE

根据此数据，如果 PlayerA 想知道他与哪些球员一起比赛，答案将是 PlayerB, PlayerC, PlayerD and PlayerE。

我现在的问题是，如果我想显示哪个玩家和谁一起玩和，那么最合乎逻辑且最容易查询的数据结构是什么？多久一次。毕竟我想向用户展示这样的图表（超级绘画技巧）：

Answer 1

你可以这样做，使用 Linq

List<List<Match> matches = ...
string player = "playerA";

var coplayers = matches.Where(x=>x.Any(p=>p.Participants.Any(s=>s.Name == player))) // get all participants where group contains participant.
           .SelectMany(x=> x.SelectMany(p=>p.Participants))                         // get all participants where group contains participant.
           .Where(x=>x.Name != player)                                              // List co participants 
           .GroupBy(x=>x.Name)                                                      // Distinct by grouping on Name or( need to override equal)
           .Select(x=>x.FirstOrDefault())
           .ToList()

勾选这个Demo

Answer 2

作为使您的解决方案更简洁的建议，让 Player 覆盖 Equals。代码如下所示：

public class Player
{
    public override bool Equals(object obj)
    {
        var other = obj as Player;
        if (other == null)
            return false;
        return this.Name == other.Name;
    }

    public override int GetHashCode()
    {
        return this.Name.GetHashCode();
    }

    public string Name;
}

这使您可以按照

的思路制定更具可读性的寻找对手的解决方案

Player me = new Player { Name = "Me" };
var allMatches = new List<Match>
{
    new Match
    {
        Participants = new List<Player> 
        {
            me,
            new Player { Name = "Some Other Dude"}
        }
    },

    new Match
    {
        Participants = new List<Player>
        {
            me,
            new Player { Name = "My Rival" }
        }
    }
};

var myMatches = allMatches.Where(m => m.Participants.Contains(me)).ToList();
var myOpponents = myMatches.SelectMany(m => m.Participants.Except(new [] {me})).Distinct();

找出我已经认识的玩家

Find out which players I've already met

c#

data-modeling