結果

問題 No.1704 Many Bus Stops (easy)
ユーザー 箱星
提出日時 2021-10-17 22:35:24
言語 Kotlin
(2.1.0)
結果
AC  
実行時間 1,152 ms / 2,000 ms
コード長 4,419 bytes
コンパイル時間 17,921 ms
コンパイル使用メモリ 458,584 KB
実行使用メモリ 88,220 KB
最終ジャッジ日時 2024-09-17 19:47:13
合計ジャッジ時間 57,119 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge1
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ファイルパターン 結果
sample AC * 1
other AC * 41
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.PrintWriter
import java.util.*

fun PrintWriter.solve() {
    val numCases = nextInt()
    case@ for (_i in 0 until numCases) {
        val n = nextLong()
        val b = arrayOf(
            arrayOf(1, 0, 0, 0, 1, 1),
            arrayOf(0, 1, 0, 1, 0, 1),
            arrayOf(0, 0, 1, 1, 1, 0),
            arrayOf(3, 0, 0, 0, 0, 0),
            arrayOf(0, 3, 0, 0, 0, 0),
            arrayOf(0, 0, 3, 0, 0, 0)
        )
        val mat = Matrix(b).pow(n).mat
        val p = mat[3][0] + ModInt(3) * mat[3][3]
        println(p / ModInt(3).pow(n + 1))
    }
}

// region Matrix
class Matrix(val mat: Array<Array<ModInt>>) {
    private val n = mat.size

    constructor(a: Array<Array<Int>>) : this(Array(a.size) { i -> Array(a.size) { j -> a[i][j].toModInt() } })
    constructor(a: Array<Array<Long>>) : this(Array(a.size) { i -> Array(a.size) { j -> a[i][j].toModInt() } })

    operator fun plus(other: Matrix): Matrix {
        val b = mat.copyOf()
        for (i in 0 until n) {
            for (j in 0 until n) {
                b[i][j] += other.mat[i][j]
            }
        }
        return Matrix(b)
    }

    operator fun minus(other: Matrix): Matrix {
        val b = mat.copyOf()
        for (i in 0 until n) {
            for (j in 0 until n) {
                b[i][j] -= other.mat[i][j]
            }
        }
        return Matrix(b)
    }

    operator fun times(other: Matrix): Matrix {
        val b = zero(n).mat
        for (k in 0 until n) {
            for (i in 0 until n) {
                for (j in 0 until n) {
                    b[i][j] += mat[i][k] * other.mat[k][j]
                }
            }
        }
        return Matrix(b)
    }

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

    override fun toString(): String {
        return mat.joinToString("\n") { "[${it.joinToString()}]" }
    }
}

fun zero(n: Int): Matrix {
    return Matrix(Array(n) { Array(n) { ModInt(0) } })
}

fun e(n: Int): Matrix {
    return Matrix(Array(n) { i -> Array(n) { j -> ModInt(if (i == j) 1 else 0) } })
}
// endregion

// region ModInt
class ModInt(x: Long) {
    companion object {
        const val MOD = 1000000007L
        //const val MOD = 998244353L
    }

    constructor(y: Int) : this(y.toLong())

    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"
    }
}

fun Long.toModInt(): ModInt {
    return ModInt(this)
}

fun Int.toModInt(): ModInt {
    return ModInt(this)
}

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

fun main() {
    Thread(null, {
        val writer = PrintWriter(System.out, !false)
        writer.solve()
        writer.flush()
    }, "solve", 1.shl(26))
        .apply { setUncaughtExceptionHandler { _, e -> e.printStackTrace(); kotlin.system.exitProcess(1) } }
        .apply { start() }.join()
}

// region Scanner
private var st = StringTokenizer("")
private val br = System.`in`.bufferedReader()

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()
// endregion
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