lab 6 task 4

lab6/Makefile

@@ -1,4 +1,4 @@
-.PHONY: run build clean task1 build-task1 clean-task1 task2 build-task2 clean-task2 task3 build-task3 clean-task3
+.PHONY: run build clean task1 build-task1 clean-task1 task2 build-task2 clean-task2 task3 build-task3 clean-task3 task4 build-task4 clean-task4
 
 # task1
 run:
@@ -41,3 +41,13 @@ build-task3:
 
 clean-task3:
 	cd task3 && dotnet clean
+
+# task4
+task4:
+	cd task4 && dotnet run --project task4.fsproj
+
+build-task4:
+	cd task4 && dotnet build
+
+clean-task4:
+	cd task4 && dotnet clean

lab6/task4/Program.fs

@@ -0,0 +1,64 @@
+type ChurchList<'a> = ('a -> 'b -> 'b) -> 'b -> 'b
+
+let nil : ChurchList<'a> = fun _ z -> z
+
+let cons (x: 'a) (xs: ChurchList<'a>) : ChurchList<'a> = 
+    fun f z -> f x (xs f z)
+
+let toList (churchList: ChurchList<'a>) : 'a list =
+    churchList (fun x acc -> x :: acc) []
+    |> List.rev
+
+let ofList (lst: 'a list) : ChurchList<'a> =
+    List.foldBack cons lst nil
+
+let foldWithPredicate (f: 'a -> 'b -> 'b) (p: 'a -> bool) (acc: 'b) (churchList: ChurchList<'a>) : 'b =
+    let rec foldTailRec lst currentAcc =
+        match lst with
+        | [] -> currentAcc
+        | x :: xs -> 
+            if p x then
+                foldTailRec xs (f x currentAcc)
+            else
+                foldTailRec xs currentAcc
+    
+    let regularList = toList churchList
+    foldTailRec regularList acc
+
+let findMin (churchList: ChurchList<int>) : int option =
+    let regularList = toList churchList
+    match regularList with
+    | [] -> None
+    | x :: xs -> 
+        let minValue = foldWithPredicate (fun x acc -> min x acc) (fun _ -> true) x churchList
+        Some minValue
+
+let sumEven (churchList: ChurchList<int>) : int =
+    foldWithPredicate (+) (fun x -> x % 2 = 0) 0 churchList
+
+let countOdd (churchList: ChurchList<int>) : int =
+    foldWithPredicate (fun _ acc -> acc + 1) (fun x -> x % 2 <> 0) 0 churchList
+
+[<EntryPoint>]
+let main argv =
+    let testList = ofList [1; 2; 3; 4; 5; 6; 7; 8; 9; 10]
+    let emptyList = nil
+    
+    printfn "Тестовый список: [1; 2; 3; 4; 5; 6; 7; 8; 9; 10]"
+    
+    match findMin testList with
+    | Some min -> printfn "Минимальный элемент: %d" min
+    | None -> printfn "Список пуст"
+    
+    printfn "Сумма четных чисел: %d" (sumEven testList)
+    printfn "Количество нечетных чисел: %d" (countOdd testList)
+    
+    printfn "\nТест с пустым списком:"
+    match findMin emptyList with
+    | Some min -> printfn "Минимальный элемент: %d" min
+    | None -> printfn "Список пуст"
+    
+    printfn "Сумма четных чисел в пустом списке: %d" (sumEven emptyList)
+    printfn "Количество нечетных чисел в пустом списке: %d" (countOdd emptyList)
+    
+    0

lab6/task4/task4.fsproj

@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+  </PropertyGroup>
+
+</Project>