c#列表项列表的组合[重复]

Question

我有一个List<TeamName>，其中TeamName 类包含List<MembersName>

所以我有这样的事情：

List<TeamName> teamNameList //each item of "tnl" has public member "memberNameList"

...

class TeamName //each team has different member
{
   public TName  
   public List<MemberName> memberNameLis;
} 

class MemberName
{
     public MName;
}

现在我想对每个团队的 MemberName 进行所有可能的组合。

例如我有 3 个团队 (T1, T2, T3)，他们的成员数为 -

T1 = 3 个成员，T2 = 2 个成员，T3 = 1 个成员，

所以现在我需要一些东西 -

T1M1 T2M1 T3M1

T1M1 T2M2 T3M1

T1M2 T2M1 T3M1

T1M2 T2M2 T3M1

T1M3 T2M1 T3M1

T1M3 T2M2 T3M1

List<List<MemberName>> combi;

如何在代码中做到这一点？ 我只是一个初学者，所以请原谅我没有以干净的方式提出问题。 请帮忙:)

Answer 1

假设您的团队列表为 -

List<TeamName> tnl;
...
...
...

// now you can call like - 
IEnumerable<IEnumerable<MemberName>> allPossible = CartesianProduct(tnl.Select(c => c.mnl));
...
...

和笛卡尔积方法会一样

IEnumerable<IEnumerable<T>> CartesianProduct<T>(IEnumerable<IEnumerable<T>> sequences)
{
    IEnumerable<IEnumerable<T>> emptyProduct = new[] { Enumerable.Empty<T>() };
    return sequences.Aggregate(
        emptyProduct,
        (accumulator, sequence) =>
            from accseq in accumulator
            from item in sequence
            select accseq.Concat(new[] { item })
        );
}

试一试，您的输入将为您提供所需的结果。

如果你会循环 -

 foreach (var item in r4)
 {
     foreach (var mn in item)
     {
         Console.Write("\t"+mn.Name);
     }
     Console.WriteLine();
 }

你会得到答案 -

T1M1    T2M1    T3M1
T1M1    T2M2    T3M1
T1M2    T2M1    T3M1
T1M2    T2M2    T3M1
T1M3    T2M1    T3M1
T1M3    T2M2    T3M1

我已经测试过了。

Answer 2

解决办法

List<TeamName> teamNameList = new List<TeamName>();
teamNameList.Add(new TeamName() { TName = "T1",
    memberNameList = new List<MemberName> {
        new MemberName { MName = "M1" },
        new MemberName { MName = "M2" },
        new MemberName { MName = "M3" } } });
teamNameList.Add(new TeamName() { TName = "T2",
    memberNameList = new List<MemberName> {
        new MemberName { MName = "M1" },
        new MemberName { MName = "M2" } } });
teamNameList.Add(new TeamName() { TName = "T3",
    memberNameList = new List<MemberName> { new MemberName { MName = "M1" } } });

List<List<MemberName>> combi = new List<List<MemberName>>();
//indexes keep index of each member for each team
List<int> indexes = new List<int>(teamNameList.Count);
//initialize them to the first members
for (int i = 0; i < teamNameList.Count; i++)
    indexes.Add(0);

//We will enumerate all combinations in this loop
while (true)
{
    //Create a new entry for combi
    List<MemberName> members = new List<MemberName>();
    //Select respective member based on the current index value for each team
    for (int i = 0; i < teamNameList.Count; i++)
        members.Add(new MemberName() { MName = teamNameList[i].TName + teamNameList[i].memberNameList[indexes[i]].MName });

    combi.Add(members);

    //Increment indexes and go to the next combination
    for (int i = indexes.Count - 1; i >= 0; i--)
    {
        indexes[i]++;
        //If we enumerated all members of the current team - start from the beginning of that members
        //Else we should proceed with the next member
        if (indexes[i] == teamNameList[i].memberNameList.Count)
            indexes[i] = 0;
        else
            break;
    }

    //If we enumerated all combinations than all indexes will become zero because of the previous loop
    if (indexes.Sum() == 0)
        break;
}