結果

問題 No.1364 [Renaming] Road to Cherry from Zelkova
ユーザー da_louisda_louis
提出日時 2021-01-24 18:29:57
言語 Kotlin
(1.9.23)
結果
WA  
実行時間 -
コード長 21,155 bytes
コンパイル時間 27,185 ms
コンパイル使用メモリ 464,316 KB
実行使用メモリ 123,064 KB
最終ジャッジ日時 2023-09-01 21:51:29
合計ジャッジ時間 68,112 ms
ジャッジサーバーID
(参考情報)
judge16 / judge11
このコードへのチャレンジ(β)

テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 320 ms
58,764 KB
testcase_01 AC 318 ms
58,808 KB
testcase_02 AC 315 ms
56,972 KB
testcase_03 WA -
testcase_04 WA -
testcase_05 WA -
testcase_06 WA -
testcase_07 WA -
testcase_08 WA -
testcase_09 WA -
testcase_10 WA -
testcase_11 WA -
testcase_12 WA -
testcase_13 WA -
testcase_14 WA -
testcase_15 WA -
testcase_16 WA -
testcase_17 WA -
testcase_18 WA -
testcase_19 WA -
testcase_20 WA -
testcase_21 WA -
testcase_22 WA -
testcase_23 AC 630 ms
67,312 KB
testcase_24 AC 547 ms
62,544 KB
testcase_25 AC 802 ms
84,796 KB
testcase_26 AC 960 ms
95,160 KB
testcase_27 AC 762 ms
81,932 KB
testcase_28 AC 711 ms
73,856 KB
testcase_29 AC 744 ms
82,824 KB
testcase_30 AC 699 ms
75,248 KB
testcase_31 AC 662 ms
67,152 KB
testcase_32 AC 730 ms
74,448 KB
testcase_33 AC 935 ms
91,300 KB
testcase_34 AC 958 ms
92,120 KB
testcase_35 AC 1,052 ms
96,348 KB
testcase_36 AC 751 ms
86,556 KB
testcase_37 AC 661 ms
74,592 KB
testcase_38 WA -
testcase_39 WA -
testcase_40 WA -
testcase_41 WA -
testcase_42 WA -
testcase_43 AC 1,049 ms
112,992 KB
testcase_44 AC 633 ms
79,512 KB
testcase_45 AC 772 ms
88,972 KB
testcase_46 AC 414 ms
61,920 KB
testcase_47 AC 323 ms
58,620 KB
権限があれば一括ダウンロードができます
コンパイルメッセージ
Main.kt:266:13: warning: 'appendln(Int): kotlin.text.StringBuilder /* = java.lang.StringBuilder */' is deprecated. Use appendLine instead. Note that the new method always appends the line feed character '\n' regardless of the system line separator.
            appendln(n)
            ^
Main.kt:299:48: warning: 'toByte(): Byte' is deprecated. Conversion of Char to Number is deprecated. Use Char.code property instead.
    private fun Byte.isNumeric() = this in '0'.toByte()..'9'.toByte()
                                               ^
Main.kt:299:62: warning: 'toByte(): Byte' is deprecated. Conversion of Char to Number is deprecated. Use Char.code property instead.
    private fun Byte.isNumeric() = this in '0'.toByte()..'9'.toByte()
                                                             ^
Main.kt:300:68: warning: 'toByte(): Byte' is deprecated. Conversion of Char to Number is deprecated. Use Char.code property instead.
    private fun Byte.toNumVal() = if (this.isNumeric()) this - '0'.toByte() else error("$this is not numeric")
                                                                   ^
Main.kt:332:22: warning: 'toByte(): Byte' is deprecated. Conversion of Char to Number is deprecated. Use Char.code property instead.
        if (b == '-'.toByte()) {
                     ^
Main.kt:358:22: warning: 'toByte(): Byte' is deprecated. Conversion of Char to Number is deprecated. Use Char.code property instead.
        if (b == '-'.toByte()) {
                     ^
Main.kt:364:22: warning: 'toByte(): Byte' is deprecated. Conversion of Char to Number is deprecated. Use Char.code property instead.
        if (b == '.'.toByte()) {
                     ^

ソースコード

diff #

import java.io.ByteArrayInputStream
import java.io.ByteArrayOutputStream
import java.io.PrintStream
import java.util.*
import kotlin.collections.ArrayDeque

fun main() = if (localEnv && execChecker) checker() else contest296g()

fun contest296g() = solve()

@OptIn(ExperimentalStdlibApi::class)
private fun solve() = Messiah_contest296g(MOD).exec {
    data class Neighbor(val index: Int, val weight: Mint)

    val (n, m) = readInt() to readInt()
    val edges = Array(m) { readInt() to readInt() to readLong().toMint() * readLong() }

    val revGraph = Array(n + 1) { mutableListOf<Int>() }
    edges.forEach { (u, v, _) -> revGraph[v].add(u) }

    // 閉路検出
    val visitedNodes = mutableSetOf<Int>()
    val queue = ArrayDeque(listOf(n))
    while (queue.isNotEmpty()) {
        val curr = queue.removeFirst()
        if (!visitedNodes.add(curr)) continue
        visitedNodes.add(curr)
        for (before in revGraph[curr]) queue.addLast(before)
    }
    val scc = SCC(n + 1).apply {
        edges.forEach { (u, v) -> if (u in visitedNodes && v in visitedNodes) addEdge(u, v) }
    }.build()
    // 0-N 間で閉路があった場合 INF 、 たどり着けない場合は 0
    when {
        0 !in visitedNodes -> "0"
        scc.size != n + 1 -> "INF"
        else -> null
    }?.let { return@exec println(it) }

    val dp = Array(n + 1) { Mint.ZERO }.apply { this[0] = Mint.ZERO }
    val graph = Array(n + 1) { mutableListOf<Neighbor>() }
    // 0-N 間の辺だけ使う
    edges.forEach { (u, v, weight) ->
        if (u in visitedNodes && v in visitedNodes) graph[u].add(Neighbor(v, weight))
    }

    for ((curr) in scc) for ((next, weight) in graph[curr]) {
        dp[next] += dp[curr] + weight
    }

    val answer = dp.last()

    println(answer)
}

/**
 * convert from [AtCoderLibraryForJava - SCC](https://github.com/NASU41/AtCoderLibraryForJava/blob/ee794a298f6d16ab24bd9316e7cae8a9155510e5/SCC/SCC.java)
 */
private class SCC(private val n: Int) {
    private class Edge(var from: Int, var to: Int)

    private var m = 0
    private val unorderedEdges: ArrayList<Edge> = ArrayList()
    private val start: IntArray = IntArray(n + 1)
    private val ids: IntArray = IntArray(n)
    private var hasBuilt = false

    fun addEdge(from: Int, to: Int) {
        rangeCheck(from)
        rangeCheck(to)
        unorderedEdges.add(Edge(from, to))
        start[from + 1]++
        m++
    }

    fun id(i: Int): Int {
        if (!hasBuilt) {
            throw UnsupportedOperationException(
                "Graph hasn't been built."
            )
        }
        rangeCheck(i)
        return ids[i]
    }

    fun build(): Array<IntArray> {
        for (i in 1..n) {
            start[i] += start[i - 1]
        }
        val orderedEdges = arrayOfNulls<Edge>(m)
        val count = IntArray(n + 1)
        System.arraycopy(start, 0, count, 0, n + 1)
        for (e in unorderedEdges) {
            orderedEdges[count[e.from]++] = e
        }
        var nowOrd = 0
        var groupNum = 0
        var k = 0
        // parent
        val par = IntArray(n)
        val vis = IntArray(n)
        val low = IntArray(n)
        val ord = IntArray(n)
        java.util.Arrays.fill(ord, -1)
        // u = lower32(stack[i]) : visiting vertex
        // j = upper32(stack[i]) : jth child
        val stack = LongArray(n)
        // size of stack
        var ptr = 0
        // non-recursional DFS
        for (i in 0 until n) {
            if (ord[i] >= 0) continue
            par[i] = -1
            // vertex i, 0th child.
            stack[ptr++] = 0L shl 32 or i.toLong()
            // stack is not empty
            while (ptr > 0) {
                // last element
                val p = stack[--ptr]
                // vertex
                val u = (p and 0xffffffffL).toInt()
                // jth child
                var j = (p ushr 32).toInt()
                if (j == 0) { // first visit
                    ord[u] = nowOrd++
                    low[u] = ord[u]
                    vis[k++] = u
                }
                if (start[u] + j < count[u]) { // there are more children
                    // jth child
                    val to = orderedEdges[start[u] + j]!!.to
                    // incr children counter
                    stack[ptr++] += 1L shl 32
                    if (ord[to] == -1) { // new vertex
                        stack[ptr++] = 0L shl 32 or to.toLong()
                        par[to] = u
                    } else { // backward edge
                        low[u] = kotlin.math.min(low[u], ord[to])
                    }
                } else { // no more children (leaving)
                    while (j-- > 0) {
                        val to = orderedEdges[start[u] + j]!!.to
                        // update lowlink
                        if (par[to] == u) low[u] = kotlin.math.min(low[u], low[to])
                    }
                    if (low[u] == ord[u]) { // root of a component
                        while (true) { // gathering verticies
                            val v = vis[--k]
                            ord[v] = n
                            ids[v] = groupNum
                            if (v == u) break
                        }
                        groupNum++ // incr the number of components
                    }
                }
            }
        }
        for (i in 0 until n) {
            ids[i] = groupNum - 1 - ids[i]
        }
        val counts = IntArray(groupNum)
        for (x in ids) counts[x]++
        val groups = Array(groupNum) { intArrayOf() }
        for (i in 0 until groupNum) {
            groups[i] = IntArray(counts[i])
        }
        for (i in 0 until n) {
            val cmp = ids[i]
            groups[cmp][--counts[cmp]] = i
        }
        hasBuilt = true
        return groups
    }

    private fun rangeCheck(i: Int) {
        if (i < 0 || i >= n) {
            throw IndexOutOfBoundsException(String.format("Index %d out of bounds for length %d", i, n))
        }
    }

}

private fun Long.toMint() = Mint(this)

@Suppress("unused")
private class Mint(value: Long) {
    constructor(other: Mint) : this(other.value)

    private val value = (value % MOD).let { if (it < 0) it + MOD else it }
    operator fun unaryPlus() = this
    operator fun unaryMinus() = Mint(MOD - this.value)
    operator fun inc() = this.plus(1)
    operator fun dec() = this.minus(1)
    operator fun plus(other: Long) = Mint(this.value + other)
    operator fun plus(other: Mint) = this.plus(other.value)
    operator fun minus(other: Long) = Mint(this.value - other)
    operator fun minus(other: Mint) = this.plus(-other)
    operator fun times(other: Long) = Mint(this.value * Mint(other).value)
    operator fun times(other: Mint) = this.times(other.value)
    operator fun div(other: Long) = this.times(other.inv())
    operator fun div(other: Mint) = this.div(other.value)
    fun inv() = Mint(modPow(this.toLong(), MOD - 2L))
    fun mod(mod: Long) = Mint(this.value % mod)
    fun pow(other: Long) = Mint(modPow(this.value, other))
    fun toLong() = this.value
    override fun toString() = this.value.toString()
    override fun hashCode() = value.hashCode()
    override fun equals(other: Any?): Boolean {
        if (this === other) return true
        if (javaClass != other?.javaClass) return false
        other as Mint
        return value == other.value
    }

    companion object {
        val ZERO = Mint(0)
        val ONE = Mint(1)
        val TWO = Mint(2)
        val TEN = Mint(10)

        private fun modPow(n: Long, p: Long): Long {
            var x = n % MOD
            var y = p
            var result = 1L
            while (y > 0) {
                if (y % 2 == 1L) result = (result * x) % MOD
                y = y shr 1
                x = (x * x) % MOD
            }
            return result
        }
    }
}

private const val MOD = 1_000_000_007

// region kokokara template dayo (^o^)
private const val execChecker = false
private val localEnv =
    runCatching { "ENABLE_DEBUG_MODE_FOR_COMPETITIVE_PROGRAMING" in System.getenv() }.getOrNull() ?: false

private fun checker() = Messiah_contest296g(MOD).exec {
    debugln("#######################################################")
    debugln("###############  executing check mode.  ###############")
    debugln("#######################################################")

    fun getOutPut(input: String, action: () -> Unit): String {
        System.setIn(ByteArrayInputStream(input.toByteArray()))
        val sysOut = ByteArrayOutputStream()
        System.setOut(PrintStream(sysOut))
        action()
        return sysOut.toString()
    }

    val wrongCases = mutableSetOf<List<String>>()

    while (wrongCases.size < 10) {
        /*
        examples
        val randomString = (1..20).map { ('a'..'z').random() }.joinToString("")
        val randomNum = Random.nextInt(0,2000)
         */
        val n = 0

        val input = buildString {
            appendln(n)
        }

        val solve = getOutPut(input, ::solve)
        val greedy = getOutPut(input, ::greedy)

        if (solve != greedy && wrongCases.add(listOf(solve, greedy))) {
            debugln("#################### wrong case: ${wrongCases.size} ####################")
            debugln("input:")
            debugln(input)
            debugln("solve:")
            debugln(solve)
            debugln("greedy:")
            debugln(greedy)
        }
    }
}

private fun greedy() = Messiah_contest296g(MOD).exec {
    TODO()
}

@Suppress("ClassName", "unused", "FunctionName", "PropertyName")
private class Messiah_contest296g(private val mod: Int) {
    //////////////////////////////////////////////////
    // IO
    //////////////////////////////////////////////////
    private val input = System.`in`
    private val buffer = ByteArray(1024)
    private var pointer = 0
    private var bufferLength = 0
    private val sb = StringBuilder()
    private fun Byte.isPrintable() = this in 33..126
    private fun Byte.isNumeric() = this in '0'.toByte()..'9'.toByte()
    private fun Byte.toNumVal() = if (this.isNumeric()) this - '0'.toByte() else error("$this is not numeric")
    private val lineSeparator: String = System.lineSeparator()

    private fun hasNextByte(): Boolean {
        return if (pointer < bufferLength) true else {
            pointer = 0
            bufferLength = input.read(buffer)
            bufferLength > 0
        }
    }

    private fun readByte(): Byte = if (hasNextByte()) buffer[pointer++] else -1
    private fun skipUnprintable() = run { while (hasNextByte() && !buffer[pointer].isPrintable()) pointer++ }
    private fun hasNext(): Boolean = run { skipUnprintable() }.run { hasNextByte() }
    private fun hasNextOrError() = if (!hasNext()) error("has no next element.") else Unit

    fun readString(): String {
        hasNextOrError()
        val sb = StringBuilder()
        var b = readByte()
        while (b.isPrintable()) {
            sb.appendCodePoint(b.toInt())
            b = readByte()
        }
        return sb.toString()
    }

    fun readLong(): Long {
        hasNextOrError()
        var n = 0L
        var negative = false
        var b = readByte()
        if (b == '-'.toByte()) {
            negative = true
            b = readByte()
        }
        if (!b.isNumeric()) error("$b is not numeric.")
        while (true) {
            when {
                b.isNumeric() -> n = n * 10 + b.toNumVal()
                b.toInt() == -1 || !b.isPrintable() -> return if (negative) -n else n
                else -> error("failed to parse. [n=$n, b=$b]")
            }
            b = readByte()
        }
    }

    fun readInt() = readLong()
        .let { if (it in Int.MIN_VALUE..Int.MAX_VALUE) it.toInt() else error("$it is not in range of Int.") }

    fun readIntAsIndex() = readInt().dec()

    fun readDouble(): Double {
        hasNextOrError()
        var n = 0.0
        var div = 1.0
        var negative = false
        var b = readByte()
        if (b == '-'.toByte()) {
            negative = true
            b = readByte()
        }
        do n = n * 10 + b.toNumVal()
        while (run { b = readByte() }.run { b.isNumeric() })
        if (b == '.'.toByte()) {
            while (run { b = readByte() }.run { b.isNumeric() })
                n += b.toNumVal() / (run { div *= 10 }.run { div })
        }
        return if (negative) -n else n
    }

    fun readString(size: Int): Array<String> = Array(size) { readString() }

    @Suppress("UNUSED_PARAMETER")
    fun readChars(h: Int, w: Int): Array<CharArray> = Array(h) { readString().toCharArray() }
    fun readLong(size: Int): LongArray = LongArray(size) { readLong() }
    fun readLong(h: Int, w: Int): Array<LongArray> = Array(h) { readLong(w) }
    fun readInt(size: Int): IntArray = IntArray(size) { readInt() }
    fun readInt(h: Int, w: Int): Array<IntArray> = Array(h) { readInt(w) }
    fun readIntAsIndex(size: Int): IntArray = IntArray(size) { readIntAsIndex() }
    fun readIntAsIndex(h: Int, w: Int): Array<IntArray> = Array(h) { readIntAsIndex(w) }
    fun readDouble(size: Int): DoubleArray = DoubleArray(size) { readDouble() }
    fun readDouble(h: Int, w: Int): Array<DoubleArray> = Array(h) { readDouble(w) }
    fun readBooleanWithSeparator(size: Int, trueElement: String): BooleanArray =
        BooleanArray(size) { readString() == trueElement }

    fun readBooleanWithSeparator(h: Int, w: Int, trueElement: String): Array<BooleanArray> =
        Array(h) { readBooleanWithSeparator(w, trueElement) }

    @Suppress("UNUSED_PARAMETER")
    fun readBooleanWithoutSeparator(size: Int, trueElement: Char): BooleanArray =
        readString().map { it == trueElement }.toBooleanArray()

    fun readBooleanWithoutSeparator(h: Int, w: Int, trueElement: Char): Array<BooleanArray> =
        Array(h) { readBooleanWithoutSeparator(w, trueElement) }

    fun println(): Unit = run { sb.append(lineSeparator) }
    fun print(any: Any): Unit = run { sb.append(any.toString()) }
    fun println(any: Any): Unit = run { sb.append(any.toString() + lineSeparator) }
    fun flush() = run { kotlin.io.println(sb); sb.clear() }
    fun debugln(any: Any): Unit = run { if (localEnv) System.err.println(any) }
    fun debugln(): Unit = run { if (localEnv) System.err.println() }
    fun debugln(action: () -> Unit): Unit = run { if (localEnv) action() }

    fun exec(action: Messiah_contest296g.() -> Unit) {
        var t: Throwable? = null
        Thread(null, { action() }, "solve", 128 * 1024 * 1024)
            .apply { setUncaughtExceptionHandler { _, t1 -> t = t1 } }
            .apply { start() }.join()
        t?.let { throw it }
        kotlin.io.print(sb)
    }

    fun readLine(): Nothing = error("readLine is disabled.")

    //////////////////////////////////////////////////
    // MOD
    //////////////////////////////////////////////////
    fun Long.invertMod(): Long = invGcd(this).second

    fun Long.safeMod(): Long = (this % MOD).let { if (it < 0) it + MOD else it }

    fun Long.modPow(p: Long): Long {
        var x = this % MOD
        var y = p
        var result = 1L
        while (y > 0) {
            if (y % 2 == 1L) result = (result * x) % MOD
            y = y shr 1
            x = (x * x) % MOD
        }
        return result
    }

    fun Long.modPow(p: Long, m: Int): Long {
        var x = this % m
        var y = p
        var result = 1L
        while (y > 0) {
            if (y % 2 == 1L) result = (result * x) % m
            y = y shr 1
            x = (x * x) % m
        }
        return result
    }

    fun invGcd(a: Long): Pair<Long, Long> {
        val am = a.safeMod()
        if (a == 0L) return MOD.toLong() to 0L
        var s = MOD.toLong()
        var t = am
        var m0 = 0L
        var m1 = 1L
        while (t != 0L) {
            val u = s / t
            s -= t * u
            m0 -= m1 * u

            var temp = s
            s = t
            t = temp
            temp = m0
            m0 = m1
            m1 = temp
        }
        if (m0 < 0) m0 += MOD / s
        return s to m0
    }

    //////////////////////////////////////////////////
    // Misc
    //////////////////////////////////////////////////
    /**
     * `n.indices()` is sugar syntax of `0 until n`.
     */
    val Int.indices: IntRange get() = 0 until this

    /**
     * `[index] in [this]` is sugar syntax of `index in 0 until [this]`.
     */
    operator fun Int.contains(index: Int): Boolean = index in this.indices

    /**
     * `[this].mapIndices { transform }` is sugar syntax of `(0 until [this]).map{ transform(it) }`.
     */
    inline fun <R> Int.mapIndices(transform: (Int) -> R): List<R> = this.indices.map(transform)

    /**
     * `[this].mapIndices(x) { transform }` is sugar syntax of
     * `(0 until [this]).map{ y1-> (0 until [x]).map { x1-> transform(y1,x1) } }`.
     */
    inline fun <R> Int.mapIndices(x: Int, transform: (Int, Int) -> R): List<List<R>> =
        this.mapIndices { y1 -> x.mapIndices { x1 -> transform(y1, x1) } }

    /**
     * `[this].mapIndices(x) { transform }` is sugar syntax of
     * `(0 until [this]).map{ y1-> (0 until [x]).map { x1-> transform(y1,x1) } }`.
     */
    inline fun <R> Int.flatMapIndices(x: Int, transform: (Int, Int) -> R): List<R> =
        this.indices.flatMap { y1 -> x.mapIndices { x1 -> transform(y1, x1) } }

    /**
     * `[this].forEachIndices { transform }` is sugar syntax of `(0 until [this]).map{ transform(it) }`.
     */
    inline fun Int.forEachIndices(transform: (Int) -> Unit): Unit = this.indices.forEach(transform)

    /**
     * `[this].forEachIndices(x) { transform }` is sugar syntax of
     * `(0 until [this]).map{ y1-> (0 until [x]).map { x1-> transform(y1,x1) } }`.
     */
    inline fun Int.forEachIndices(x: Int, transform: (Int, Int) -> Unit): Unit =
        this.forEachIndices { y1 -> x.forEachIndices { x1 -> transform(y1, x1) } }

    /**
     * get characters numeric value.
     * e.g.: '0' to 0
     */
    fun Char.toNumericValue(): Int = this - '0'

    fun Char.caseToIndexedValue(): Int = this - 'a'

    //    fun Char.isLowerCase() = this in 'a'..'z'
    //
    //    fun Char.isUpperCase() = this in 'A'..'Z'

    /**
     * make triple. e.g.:`1 to 2 to 3`
     */
    infix fun <A, B, C> Pair<A, B>.to(c: C): Triple<A, B, C> = Triple(this.first, this.second, c)

    fun YesNo(b: Boolean): String = if (b) Yes else No
    val Yes = "Yes"
    val No = "No"
    fun YES_NO(b: Boolean): String = if (b) YES else NO
    val YES = "YES"
    val NO = "NO"

    fun IntArray.swap(a: Int, b: Int): Unit = run { val temp = this[a]; this[a] = this[b]; this[b] = temp }
    fun LongArray.swap(a: Int, b: Int): Unit = run { val temp = this[a]; this[a] = this[b]; this[b] = temp }
    fun CharArray.swap(a: Int, b: Int): Unit = run { val temp = this[a]; this[a] = this[b]; this[b] = temp }
    fun <T> Array<T>.swap(a: Int, b: Int): Unit = run { val temp = this[a]; this[a] = this[b]; this[b] = temp }
    fun <T> MutableList<T>.swap(a: Int, b: Int): Unit = run { val temp = this[a]; this[a] = this[b]; this[b] = temp }

    fun IntArray.changeMinOf(i: Int, v: Int): Unit = run { this[i] = kotlin.math.min(this[i], v) }
    fun IntArray.changeMaxOf(i: Int, v: Int): Unit = run { this[i] = kotlin.math.max(this[i], v) }
    fun LongArray.changeMinOf(i: Int, v: Long): Unit = run { this[i] = kotlin.math.min(this[i], v) }
    fun LongArray.changeMaxOf(i: Int, v: Long): Unit = run { this[i] = kotlin.math.max(this[i], v) }

    /**
     * same usage as `IntArray.scan`, but it will faster than that.
     */
    inline fun IntArray.scanArray(initial: Int, operation: (acc: Int, Int) -> Int): IntArray {
        val accumulator = IntArray(this.size + 1).apply { this[0] = initial }
        for (i in this.indices) accumulator[i + 1] = operation(accumulator[i], this[i])
        return accumulator
    }

    /**
     * same usage as `LongArray.scan`, but it will faster than that.
     */
    inline fun LongArray.scanArray(initial: Long, operation: (acc: Long, Long) -> Long): LongArray {
        val accumulator = LongArray(this.size + 1).apply { this[0] = initial }
        for (i in this.indices) accumulator[i + 1] = operation(accumulator[i], this[i])
        return accumulator
    }

    /**
     * same usage as `IntArray.scanReduce`, but it will faster than that.
     */
    inline fun IntArray.scanReduceArray(operation: (acc: Int, Int) -> Int): IntArray {
        val accumulator = IntArray(this.size).apply { this[0] = this@scanReduceArray[0] }
        for (i in 1..this.lastIndex) accumulator[i] = operation(accumulator[i - 1], this[i])
        return accumulator
    }

    /**
     * same usage as `LongArray.scanReduce`, but it will faster than that.
     */
    inline fun LongArray.scanReduceArray(operation: (acc: Long, Long) -> Long): LongArray {
        val accumulator = LongArray(this.size).apply { this[0] = this@scanReduceArray[0] }
        for (i in 1..this.lastIndex) accumulator[i] = operation(accumulator[i - 1], this[i])
        return accumulator
    }
}
// endregion kokomade template dayo (^o^)
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