paiza Online Hackathon 4 Lite : Answers with F#

mission1.fs

// https://paiza.jp/poh/enkoi-second/e144f4da
open System

let readLines (reader : IO.TextReader) =
    seq {
        let eof = ref false
        while not !eof do
            match reader.ReadLine() with
            | null -> eof := true
            | str -> yield str
    }

[<EntryPoint>]
let main args =
    let result = readLines Console.In
                 |> Seq.skip 1
                 |> Seq.map int
                 |> Seq.sum
    Console.WriteLine(result)
    0

mission2.fs

// https://paiza.jp/poh/enkoi-third/357303dc
open System

let readLines (reader : IO.TextReader) =
    seq {
        let eof = ref false
        while not !eof do
            match reader.ReadLine() with
            | null -> eof := true
            | str -> yield str
    }

[<EntryPoint>]
let main args =
    let result = readLines Console.In
                 |> Seq.skip 1
                 |> Seq.map (fun s -> s.Trim().Split([|' '|]) |> (Array.map int))
                 |> Seq.sumBy (fun item -> max 0 ((item.[0] - item.[1]) * item.[2]))
    printfn "%d" result
    0

mission3.fs

// https://paiza.jp/poh/enkoi-ending/6dfbbfb3
open System

let readLines (reader : IO.TextReader) =
    seq {
        let eof = ref false
        while not !eof do
            match reader.ReadLine() with
            | null -> eof := true
            | str -> yield str
    }

[<EntryPoint>]
let main args =
    let tmp = Console.ReadLine().Split([|' '|])
    let t = int tmp.[0]
    let n = int tmp.[1]
    let sum = readLines Console.In
              |> Seq.map int
              |> Seq.scan (fun acc elem -> acc + elem) 0
              |> Seq.toArray
    
    let result = seq { 1 .. (n - t + 1) }
                 |> Seq.map (fun i -> sum.[i + t - 1] - sum.[i - 1])
                 |> Seq.max
    printfn "%d" result
    0