В C # вы бы включили ссылку на соседние узлы. Но с вашим определением у вас есть узел Neighbor, что делает его невыполнимой задачей.
Помимо решения @kvb есть и другие варианты:
Вариант 1: использовать string list
Для меня было бы гораздо разумнее сделать список ссылающимся на имя узла, а не на сам узел:
type Node =
{
Name : string
Neighbors: string list
}
Сначала некоторые вспомогательные функции:
let addRelation relations (node1, node2) =
relations
|> Set.add (node1, node2)
|> Set.add (node2, node1)
let allRelations nodes =
nodes |> List.fold addRelation Set.empty
Это был бы способ создать его:
let getNodes nodes =
let rels = allRelations nodes
rels
|> Seq.groupBy fst
|> Seq.map (fun (name, neighbors) ->
{ Name = name
Neighbors = neighbors |> Seq.map snd |> Seq.toList
}
)
|> Seq.toList
и в основном вы предоставляете ему список с парой имен:
["1", "2"
"3", "4"
"1", "3"
"4", "5" ]
|> getNodes
|> Seq.iter (printfn "%A")
производит:
{Name = "1";
Neighbors = ["2"; "3"];}
{Name = "2";
Neighbors = ["1"];}
{Name = "3";
Neighbors = ["1"; "4"];}
{Name = "4";
Neighbors = ["3"; "5"];}
{Name = "5";
Neighbors = ["4"];}
Вариант 2: ref до Node list
У вас может быть ссылка на список соседних узлов:
type Node =
{
Name : string
Neighbors: Node list ref
}
Таким образом, вы можете сначала создать узлы, а затем добавить их в списки:
let getNodes nodePairs =
let rels = allRelations nodePairs
let nodes = rels |> Seq.map (fun (name, _) -> name, { Name = name ; Neighbors = ref [] }) |> Map
let getNode nm = nodes |> Map.find nm
rels
|> Seq.groupBy fst
|> Seq.iter (fun (name, neighbors) ->
(getNode name).Neighbors := neighbors |> Seq.map (snd >> getNode) |> Seq.toList
)
nodes |> Map.toList |> List.map snd
Проверьте это так:
["1", "2"
"3", "4"
"1", "3"
"4", "5" ]
|> getNodes
|> Seq.iter (printfn "%A")
выход:
{Name = "1";
Neighbors =
{contents =
[{Name = "2";
Neighbors = {contents = [...];};};
{Name = "3";
Neighbors =
{contents =
[...;
{Name = "4";
Neighbors = {contents = [...; {Name = "5";
Neighbors = {contents = [...];};}];};}];};}];};}
{Name = "2";
Neighbors =
{contents =
[{Name = "1";
Neighbors =
{contents =
[...;
{Name = "3";
Neighbors =
{contents =
[...;
{Name = "4";
Neighbors =
{contents = [...; {Name = "5";
Neighbors = {contents = [...];};}];};}];};}];};}];};}
{Name = "3";
Neighbors =
{contents =
[{Name = "1";
Neighbors = {contents = [{Name = "2";
Neighbors = {contents = [...];};}; ...];};};
{Name = "4";
Neighbors = {contents = [...; {Name = "5";
Neighbors = {contents = [...];};}];};}];};}
{Name = "4";
Neighbors =
{contents =
[{Name = "3";
Neighbors =
{contents =
[{Name = "1";
Neighbors = {contents = [{Name = "2";
Neighbors = {contents = [...];};}; ...];};};
...];};}; {Name = "5";
Neighbors = {contents = [...];};}];};}
{Name = "5";
Neighbors =
{contents =
[{Name = "4";
Neighbors =
{contents =
[{Name = "3";
Neighbors =
{contents =
[{Name = "1";
Neighbors =
{contents = [{Name = "2";
Neighbors = {contents = [...];};}; ...];};}; ...];};};
...];};}];};}