結果

問題 No.1238 選抜クラス
ユーザー 箱星
提出日時 2020-09-25 21:53:20
言語 Kotlin
(2.1.0)
結果
TLE  
実行時間 -
コード長 3,400 bytes
コンパイル時間 14,905 ms
コンパイル使用メモリ 459,880 KB
実行使用メモリ 240,076 KB
最終ジャッジ日時 2024-06-28 06:29:35
合計ジャッジ時間 24,511 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge4
このコードへのチャレンジ
（要ログイン）
ファイルパターン 結果
sample AC * 3
other AC * 14 TLE * 1 -- * 21
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 # 

import java.io.BufferedReader
import java.io.InputStream
import java.io.InputStreamReader
import java.io.PrintWriter
import java.util.*

// ModInt
// region
class ModInt(x: Long) {

    companion object {
        const val MOD = 1000000007L
        //const val MOD = 998244353L
    }

    val x = (x % MOD + MOD) % MOD

    operator fun plus(other: ModInt): ModInt {
        return ModInt(x + other.x)
    }

    operator fun minus(other: ModInt): ModInt {
        return ModInt(x - other.x)
    }

    operator fun times(other: ModInt): ModInt {
        return ModInt(x * other.x)
    }

    operator fun div(other: ModInt): ModInt {
        return this * other.inv()
    }

    fun pow(exp: Long): ModInt {
        if (exp == 0L) return ModInt(1L)
        var a = pow(exp shr 1)
        a *= a
        if (exp and 1L == 0L) return a
        return this * a
    }

    fun inv(): ModInt {
        return this.pow(MOD - 2)
    }

    override fun equals(other: Any?): Boolean {
        if (this === other) return true
        if (javaClass != other?.javaClass) return false

        other as ModInt

        if (x != other.x) return false

        return true
    }

    override fun hashCode(): Int {
        return x.hashCode()
    }

    override fun toString(): String {
        return "$x"
    }

}

val fac = mutableListOf<ModInt>()
val invfac = mutableListOf<ModInt>()

fun fact(n: Long, b: Boolean): ModInt {
    if (fac.count() == 0) {
        fac.add(ModInt(1))
        invfac.add(ModInt(1))
    }
    while (fac.count() <= n) {
        fac.add(fac.last() * ModInt(fac.count().toLong()))
        invfac.add(fac.last().inv())
    }
    return if (b) {
        fac[n.toInt()]
    } else {
        invfac[n.toInt()]
    }
}

fun comb(n: Long, k: Long): ModInt {
    return fact(n, true) * fact(k, false) * fact(n - k, false)
}

fun comb2(n: Long, k: Long): ModInt {
    var ans = ModInt(1)
    for (i in 0 until k) {
        ans = ans * ModInt(n - i) / ModInt(k - i)
    }
    return ans
}
// endregion

fun PrintWriter.solve(sc: FastScanner) {
    val n = sc.nextInt()
    val a = sc.nextInt()
    val x = Array(n) { sc.nextInt() }
    val size = 100 * n + 1
    var dp = Array(n + 1) { Array(size) { ModInt(0) } }
    dp[0][0] = ModInt(1)
    for (i in 0 until n) {
        val newdp = Array(n + 1) { Array(size) { ModInt(0) } }
        for (j in 0..n) {
            for (k in 0 until size) {
                if (j > 0 && k >= x[i]) {
                    newdp[j][k] = dp[j][k] + dp[j - 1][k - x[i]]
                } else {
                    newdp[j][k] = dp[j][k]
                }
            }
        }
        dp = newdp
    }
    var ans = ModInt(0)
    for (i in 1..n) {
        if (i * a >= size) break
        for (b in i * a until size) {
            ans += dp[i][b]
        }
    }
    println(ans)
}

fun main() {
    val writer = PrintWriter(System.out, false)
    writer.solve(FastScanner(System.`in`))
    writer.flush()
}

class FastScanner(s: InputStream) {
    private var st = StringTokenizer("")
    private val br = BufferedReader(InputStreamReader(s))

    fun next(): String {
        while (!st.hasMoreTokens()) st = StringTokenizer(br.readLine())

        return st.nextToken()
    }

    fun nextInt() = next().toInt()
    fun nextLong() = next().toLong()
    fun nextLine() = br.readLine()
    fun nextDouble() = next().toDouble()
    fun ready() = br.ready()
}
0