我正在解决与嵌套组相关的问题。我需要确定一个组是其成员的所有组以及作为其成员的所有组。不仅是直接的父母和孩子，而且层级中的每个人都在上下。
到目前为止，我所做的是从上到下的遍历逻辑，即DFS使用堆栈存储未访问的注释，以及用于存储访问过的注释的哈希集。这样，如果结果图中有任何循环，我们就不会进入无限递归。
static HashSet<string> visited = new HashSet<string>();
static Stack<string> notVisited = new Stack<string>();
static Dictionary<string, HashSet<string>> groupMembers = new Dictionary<string, HashSet<string>>
{
{ "G4", new HashSet<string> { "G5","G6","U1","U2"} },
{ "G1", new HashSet<string> { "G2","G3","G6"} },
{ "G3", new HashSet<string> { "G4"} },
{ "G2", new HashSet<string> { "G4","G1"} },
{ "G5", new HashSet<string> { "G2"} },
{ "G6", new HashSet<string> { "U2","G5"} },
};
static void Init(string start)
{
notVisited.Push(start);
while (notVisited.Count > 0)
{
string next = notVisited.Pop();
HashSet<string> found;
if (visited.Add(next) && groupMembers.TryGetValue(next, out found))
{
foreach (string member in found)
{
notVisited.Push(member);
}
}
}
}
这部分有效。我遇到的问题是，弄清楚如何在遍历过程中为每个小组存储父母和孩子。请记住，一个群组可以将其他群组或用户作为成员，我们也不想存储重复的信息。
输出应该看起来像一个组列表如下：
private class MyGroup
{
public string Identity { get; set; }
public HashSet<string> MemberOf { get; set; }
public HashSet<string> Members { get; set; }
public HashSet<string> Users { get; set; }
}
答案 0 :(得分：1)
我不确定我是否正确理解，因为您似乎已经使用visited HashSet解决了这个问题。只需将Init中的本地变量和返回作为操作的结果：
class Program
{
static Dictionary<string, HashSet<string>> groupMembers = new Dictionary<string, HashSet<string>>
{
{ "G4", new HashSet<string> { "G5","G6","U1","U2"} },
{ "G1", new HashSet<string> { "G2","G3","G6"} },
{ "G3", new HashSet<string> { "G4"} },
{ "G2", new HashSet<string> { "G4","G1"} },
{ "G5", new HashSet<string> { "G2"} },
{ "G6", new HashSet<string> { "U2","G5"} },
};
static void Main()
{
foreach(string start in groupMembers.Keys)
{
HashSet<string> result = Init(start);
Console.WriteLine("Start @ " + start + ": " + String.Join(", ", result.ToArray()));
}
Console.Write("Press Enter to Quit");
Console.ReadLine();
}
static HashSet<string> Init(string start)
{
HashSet<string> visited = new HashSet<string>();
Stack<string> notVisited = new Stack<string>();
notVisited.Push(start);
while (notVisited.Count > 0)
{
string next = notVisited.Pop();
HashSet<string> children;
if (visited.Add(next) && groupMembers.TryGetValue(next, out children))
{
foreach (string member in children)
{
notVisited.Push(member);
}
}
}
visited.Remove(start); // optionally remove "start" from the result?
return visited;
}
}
输出：
Start @ G4: U2, U1, G6, G5, G2, G1, G3
Start @ G1: G6, G5, G2, G4, U2, U1, G3
Start @ G3: G4, U2, U1, G6, G5, G2, G1
Start @ G2: G1, G6, G5, U2, G3, G4, U1
Start @ G5: G2, G1, G6, U2, G3, G4, U1
Start @ G6: G5, G2, G1, G3, G4, U2, U1
Press Enter to Quit
-----编辑-----
根据新要求，我想〜这就是你想要的：
class Program
{
private class MyGroup
{
public string Identity { get; set; }
public HashSet<string> MemberOf { get; set; }
public HashSet<string> Members { get; set; }
public HashSet<string> Users { get; set; }
public override string ToString()
{
StringBuilder sb = new StringBuilder();
sb.AppendLine("Identity: " + Identity);
sb.AppendLine("MemberOf: " + String.Join(", ", MemberOf.ToArray()));
sb.AppendLine("Members: " + String.Join(", ", Members.ToArray()));
sb.AppendLine("Users: " + String.Join(", ", Users.ToArray()));
return sb.ToString();
}
}
static Dictionary<string, HashSet<string>> groupMembers = new Dictionary<string, HashSet<string>>
{
{ "G4", new HashSet<string> { "G5","G6","U1","U2"} },
{ "G1", new HashSet<string> { "G2","G3","G6"} },
{ "G3", new HashSet<string> { "G4"} },
{ "G2", new HashSet<string> { "G4","G1"} },
{ "G5", new HashSet<string> { "G2"} },
{ "G6", new HashSet<string> { "U2","G5"} },
};
static void Main()
{
Dictionary<string, MyGroup> output = new Dictionary<string, MyGroup>();
// First Pass: Figure out Children and Users
foreach(string start in groupMembers.Keys)
{
MyGroup group = new MyGroup();
group.Identity = start;
HashSet<string> Users = new HashSet<string>();
group.Members = GetChildrenAndUsers(start, ref Users);
group.Users = Users;
output.Add(start, group);
}
// Second Pass: Figure out the Parents:
List<string> outer = output.Keys.ToList();
List<string> inner = output.Keys.ToList();
foreach (string outerKey in outer)
{
MyGroup group = output[outerKey];
group.MemberOf = new HashSet<string>();
foreach (string innerKey in inner)
{
MyGroup group2 = output[innerKey];
if (group2.Identity != group.Identity)
{
if(group2.Members.Contains(group.Identity))
{
group.MemberOf.Add(group2.Identity);
}
}
}
}
// Display the results:
foreach(MyGroup group in output.Values)
{
Console.Write(group.ToString());
Console.WriteLine("--------------------------------------------------");
}
Console.Write("Press Enter to Quit");
Console.ReadLine();
}
static HashSet<string> GetChildrenAndUsers(string start, ref HashSet<string> Users)
{
HashSet<string> visited = new HashSet<string>();
Stack<string> notVisited = new Stack<string>();
notVisited.Push(start);
while (notVisited.Count > 0)
{
string next = notVisited.Pop();
HashSet<string> children;
if (!groupMembers.ContainsKey(next))
{
Users.Add(next);
}
else
{
if (visited.Add(next) && groupMembers.TryGetValue(next, out children))
{
foreach (string member in children)
{
notVisited.Push(member);
}
}
}
}
visited.Remove(start); // optionally remove "start" from the result?
return visited;
}
}
输出：
Identity: G4
MemberOf: G1, G3, G2, G5, G6
Members: G6, G5, G2, G1, G3
Users: U2, U1
--------------------------------------------------
Identity: G1
MemberOf: G4, G3, G2, G5, G6
Members: G6, G5, G2, G4, G3
Users: U2, U1
--------------------------------------------------
Identity: G3
MemberOf: G4, G1, G2, G5, G6
Members: G4, G6, G5, G2, G1
Users: U2, U1
--------------------------------------------------
Identity: G2
MemberOf: G4, G1, G3, G5, G6
Members: G1, G6, G5, G3, G4
Users: U2, U1
--------------------------------------------------
Identity: G5
MemberOf: G4, G1, G3, G2, G6
Members: G2, G1, G6, G3, G4
Users: U2, U1
--------------------------------------------------
Identity: G6
MemberOf: G4, G1, G3, G2, G5
Members: G5, G2, G1, G3, G4
Users: U2, U1
--------------------------------------------------
Press Enter to Quit