F#: 有効文字数 759 文字(うわー、私はこれが苦手です ;) )
最小化されたバージョン
open System.Text.RegularExpressions
type t=T of float*(string*t*t)option
let rec e=function x,T(w,Some(s,a,b))->e(x,if Set.contains s x then a else b)*w|x,T(w,_)->w
let rec h x=Regex.Matches(x, @"\(|\)|\d\.\d+|\S+")|>Seq.cast<Match>|>Seq.map (fun x -> x.Value)|> Seq.toList
let rec p=function ")"::y->p y|"("::w::x::y->match x with ")"->T(float w,None),y|n->let a,f=p y in let b,g=p f in T(float w,Some(n,a,b)),g
let solve input =
Regex.Matches(input,@"(\(((?<s>\()|[^()]|(?<-s>\)))*\)(?(s)(?!)))\s+\d+\s+((\S+\s\d(.+)?\s*)+)")
|>Seq.cast<Match>
|>Seq.map(fun m->fst(p(h(m.Groups.[1].Value))), [for a in m.Groups.[3].Value.Trim().Split([|'\n'|])->set(a.Split([|' '|]))])
|>Seq.iteri(fun i (r,c)->printfn"Case #%i"(i+1);c|>Seq.iter(fun x->printfn"%.7F"(e(x, r))))
可読版
open System.Text.RegularExpressions
type decisionTree = T of float * (string * decisionTree * decisionTree) option
let rec eval = function
| x, T(w, Some(s, a, b)) -> eval(x, if Set.contains s x then a else b) * w
| x, T(w, _) -> w
// creates a token stream
let rec tokenize tree =
Regex.Matches(tree, @"\(|\)|\d\.\d+|\S+")
|> Seq.cast<Match>
|> Seq.map (fun x -> x.Value)
|> Seq.toList
// converts token stream into a decisionTree
let rec parse = function
| ")"::xs -> parse xs
| "("::weight::x::xs ->
match x with
| ")" -> T(float weight, None), xs
| name ->
let t1, xs' = parse xs
let t2, xs'' = parse xs'
T(float weight, Some(name, t1, t2)), xs''
// uses regex to transform input file into a Seq<decisionTree, list<set<string>>, which each item in our
// list will be tested against the decisionTree
let solve input =
Regex.Matches(input, @"(\(((?<s>\()|[^()]|(?<-s>\)))*\)(?(s)(?!)))\s+\d+\s+((\S+\s\d(.+)?\s*)+)")
|> Seq.cast<Match>
|> Seq.map (fun m -> fst(parse(tokenize(m.Groups.[1].Value))), [for a in m.Groups.[3].Value.Trim().Split([|'\n'|]) -> set(a.Split([|' '|])) ])
|> Seq.iteri (fun i (tree, testCases) ->
printfn "Case #%i" (i+1)
testCases |> Seq.iter (fun testCase -> printfn "%.7F" (eval (testCase, tree)))
)