F#初试（2）

  这里只是几个f#简单的算法应用，请各位别怕砖。

 1 // Learn more about F# at http://fsharp.net
 2 
 3 #light
 4 open System
 5 
 6 
 7 //简单的网页抓取
 8 open System.Text
 9 open System.IO
10 open System.Net
11 let http (url:string)=
12     let request=System.Net.WebRequest.Create(url)
13     let response=request.GetResponse()
14     let stream=response.GetResponseStream()
15     let reader=new System.IO.StreamReader(stream)
16     let html =reader.ReadToEnd();
17     html
18 printfn "%s" (http "http://www.google.com")
19 
20 //汉罗塔问题：
21 let rec HanLiTa n a b c =
22     match n with
23     | 1 -> printfn " Move %s to %s ;"  a c
24     | num ->  HanLiTa (num-1) a c b ;HanLiTa 1 a b c ; HanLiTa (num-1) b a c ;
25 
26 let n=4
27 printfn "HanLiTa start (%d):" n
28 HanLiTa n "A" "B" "C"
29 
30 //Fibonacci基数
31 
32 let rec Fib n = 
33     match n with
34     |2 |1 -> 1
35     |i when i >1 -> Fib (i-1) + Fib (i-2)
36     |x  when x<= 0 -> failwith " you should input a Interger;"
37 
38 let fibn=5    
39 printfn "Fibonacci %d : %d"     fibn (Fib fibn)
40 
41 
42 //杨辉三角
43 let rec combi n r =
44     let p=ref 1;
45     [1 .. r] |> List.iter(fun g ->  p:=!p*(n-g+1)/g );
46     !p
47 
48 let CombiPrint N=
49     [0 .. N] |>
50          List.iter(fun g -> ([0 .. g] |>
51                                     List.iter(fun h-> 
52                                                 if h=0 then 
53                                                     [0..(N-g)] |>
54                                                              List.iter(fun s->printf "  ") ; 
55                                                 printf "%5d" (combi g h));
56                         printf "\r\n"));
57 
58 printfn "\r\n杨辉三角:"
59 CombiPrint 10
60 
61 
62 Console.Read() |>ignore