結果

問題 No.1238 選抜クラス
コンテスト
ユーザー semisagi
提出日時 2020-09-25 21:46:09
言語 Swift
(6.0.3)
結果
AC  
実行時間 13 ms / 2,000 ms
コード長 3,296 bytes
コンパイル時間 14,242 ms
コンパイル使用メモリ 132,444 KB
実行使用メモリ 9,600 KB
最終ジャッジ日時 2024-06-28 06:20:00
合計ジャッジ時間 14,044 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge2
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ファイルパターン 結果
sample AC * 3
other AC * 36
権限があれば一括ダウンロードができます

ソースコード

diff # 

struct Scanner {
    private var elements = [String]()
    private var index = 0

    mutating func peek() -> String {
        while elements.count == index {
            elements = readLine()!.split(separator: " ").map(String.init)
            index = 0
        }
        return elements[index]
    }

    mutating func next() -> String {
        let value = peek()
        index += 1
        return value
    }

    mutating func nextInt() -> Int {
        return Int(next())!
    }

    mutating func nextDouble() -> Double {
        return Double(next())!
    }
}

let MOD = 1000000007

struct Zn: CustomStringConvertible {
    let n: Int

    init(_ n: Int) {
        self.n = n
    }

    var description: String {
        String(self.n)
    }

    static var zero = Zn(0)
    static var one = Zn(1)

    static func + (lhs: Self, rhs: Self) -> Self {
        let n = lhs.n + rhs.n
        return Zn(n < MOD ? n : n - MOD)
    }

    static func + (lhs: Self, rhs: Int) -> Self {
        return lhs + Zn(rhs)
    }

    static func + (lhs: Int, rhs: Self) -> Self {
        return Zn(lhs) + rhs
    }

    static func - (lhs: Self, rhs: Self) -> Self {
        let n = lhs.n - rhs.n
        return Zn(n >= 0 ? n : n + MOD)
    }

    static func - (lhs: Self, rhs: Int) -> Self {
        return lhs - Zn(rhs)
    }

    static func - (lhs: Int, rhs: Self) -> Self {
        return Zn(lhs) - rhs
    }

    static func * (lhs: Self, rhs: Self) -> Self {
        Zn((lhs.n * rhs.n) % MOD)
    }

    static func * (lhs: Self, rhs: Int) -> Self {
        return lhs * Zn(rhs)
    }

    static func * (lhs: Int, rhs: Self) -> Self {
        return Zn(lhs) * rhs
    }

    static func += (lhs: inout Self, rhs: Self) {
        lhs = lhs + rhs
    }

    static func += (lhs: inout Self, rhs: Int) {
        lhs = lhs + Zn(rhs)
    }

    static func -= (lhs: inout Self, rhs: Self) {
        lhs = lhs - rhs
    }

    static func -= (lhs: inout Self, rhs: Int) {
        lhs = lhs - Zn(rhs)
    }

    static func *= (lhs: inout Self, rhs: Self) {
        lhs = lhs * rhs
    }

    static func *= (lhs: inout Self, rhs: Int) {
        lhs = lhs * Zn(rhs)
    }

    func pow(_ n: Int) -> Self {
        if n == 0 {
            return Zn(1)
        } else if n % 2 == 1 {
            return self * self.pow(n - 1)
        } else {
            return (self * self).pow(n / 2)
        }
    }

    var inverse: Self {
        self.pow(MOD - 2)
    }
}

struct Array2D<Element> {
    let n1: Int
    let n2: Int
    private var elements: [Element]

    init(repeating: Element, _ n1: Int, _ n2: Int) {
        self.n1 = n1
        self.n2 = n2
        self.elements = [Element](repeating: repeating, count: n1 * n2)
    }

    subscript(i: Int, j: Int) -> Element {
        get {
            elements[i * n2 + j]
        }
        set {
            elements[i * n2 + j] = newValue
        }
    }
}

var scanner = Scanner()
let N = scanner.nextInt()
let K = scanner.nextInt()

let A = (0 ..< N).map { _ in scanner.nextInt() }

var dp = [Zn](repeating: Zn(0), count: 20001)

dp[10000] = Zn(1)

for i in 0 ..< N {
    let from = dp
    for j in 0 ... 20000 where from[j].n != 0 {
        dp[j + A[i] - K] += from[j]
    }
}

let answer = dp[10000 ... 20000].reduce(Zn(0), +) - Zn(1)
print(answer)
0