結果

問題 No.1103 Directed Length Sum
ユーザー yakamotoyakamoto
提出日時 2020-07-03 22:12:16
言語 Kotlin
(1.9.23)
結果
AC  
実行時間 1,330 ms / 3,000 ms
コード長 3,678 bytes
コンパイル時間 16,089 ms
コンパイル使用メモリ 464,304 KB
実行使用メモリ 117,716 KB
最終ジャッジ日時 2023-10-17 03:55:03
合計ジャッジ時間 36,843 ms
ジャッジサーバーID
（参考情報） 		judge15 / judge13
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 301 ms
55,380 KB
testcase_01 AC 301 ms
55,400 KB
testcase_02 AC 1,044 ms
115,164 KB
testcase_03 AC 1,065 ms
117,388 KB
testcase_04 AC 939 ms
84,212 KB
testcase_05 AC 1,330 ms
117,716 KB
testcase_06 AC 764 ms
80,004 KB
testcase_07 AC 593 ms
63,436 KB
testcase_08 AC 657 ms
63,236 KB
testcase_09 AC 532 ms
61,332 KB
testcase_10 AC 672 ms
67,516 KB
testcase_11 AC 992 ms
97,868 KB
testcase_12 AC 774 ms
79,856 KB
testcase_13 AC 666 ms
67,500 KB
testcase_14 AC 511 ms
61,076 KB
testcase_15 AC 719 ms
73,784 KB
testcase_16 AC 1,014 ms
103,456 KB
testcase_17 AC 1,092 ms
103,680 KB
testcase_18 AC 678 ms
67,476 KB
testcase_19 AC 1,022 ms
88,452 KB
testcase_20 AC 552 ms
61,368 KB
testcase_21 AC 663 ms
65,496 KB
testcase_22 AC 895 ms
86,260 KB
testcase_23 AC 745 ms
75,968 KB
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.util.*
import kotlin.math.abs
import kotlin.math.max
import kotlin.math.min

val MOD = 1_000_000_007L
/**
 * (dist, parent, queue)
 */
fun traceBfs(g: Array<IntArray>, rt: Int = 0): Array<IntArray> {
  val n = g.size
  val q = IntArray(n)
  val d = IntArray(n)
  val p = IntArray(n){-2}
  var cur = 0
  var last = 1
  p[rt] = -1
  q[0] = rt
  d[rt] = 0
  while (cur < last) {
    val v = q[cur++]
    for (u in g[v]) {
      if (p[u] == -2) {
        p[u] = v
        q[last++] = u
        d[u] = d[v] + 1
      }
    }
  }
  return arrayOf(d, p, q)
}
fun packDGraph(n: Int, from: IntArray, to: IntArray): Array<IntArray> {
  val p = IntArray(n)
  val m = from.size
  for (i in 0 until m) {
    ++p[from[i]]
  }
  val g = Array(n){IntArray(p[it])}
  for (i in 0 until m) {
    g[from[i]][--p[from[i]]] = to[i]
  }
  return g
}
class Solver(stream: InputStream, private val out: java.io.PrintWriter) {
  fun solve() {
    val N = ni()
    val (from, to) = na2(N - 1, -1)
    val g = packDGraph(N, from, to)
    val flg = BooleanArray(N){true}
    for (i in 0 until N - 1) {
      flg[to[i]] = false
    }
    val rt = flg.indexOf(true)
    val (_, par, que) = traceBfs(g, rt)
    val dpCnt = IntArray(N){1}
    val dpV = LongArray(N)
    for (i in N - 1 downTo 0) {
      val u = que[i]
      for (v in g[u]) {
        if (par[u] == v) continue
        dpCnt[u] += dpCnt[v]
        dpV[u] = (dpV[u] + dpV[v] + dpCnt[v]) % MOD
      }
    }
    debug(dpCnt)
    debug(dpV)
    out.println(dpV.sum() % MOD)
  }













































  private val isDebug = try {
    // なんか本番でエラーでる
    System.getenv("MY_DEBUG") != null
  } catch (t: Throwable) {
    false
  }

  private var tokenizer: StringTokenizer? = null
  private val reader = BufferedReader(InputStreamReader(stream), 32768)
  private fun next(): String {
    while (tokenizer == null || !tokenizer!!.hasMoreTokens()) {
      tokenizer = StringTokenizer(reader.readLine())
    }
    return tokenizer!!.nextToken()
  }

  private fun ni() = next().toInt()
  private fun nl() = next().toLong()
  private fun ns() = next()
  private fun na(n: Int, offset: Int = 0): IntArray {
    return map(n) { ni() + offset }
  }
  private fun nal(n: Int, offset: Int = 0): LongArray {
    val res = LongArray(n)
    for (i in 0 until n) {
      res[i] = nl() + offset
    }
    return res
  }

  private fun na2(n: Int, offset: Int = 0): Array<IntArray> {
    val a  = Array(2){IntArray(n)}
    for (i in 0 until n) {
      for (e in a) {
        e[i] = ni() + offset
      }
    }
    return a
  }

  private inline fun map(n: Int, f: (Int) -> Int): IntArray {
    val res = IntArray(n)
    for (i in 0 until n) {
      res[i] = f(i)
    }
    return res
  }

  private inline fun debug(msg: () -> String) {
    if (isDebug) System.err.println(msg())
  }

  private fun debug(a: LongArray) {
    debug { a.joinToString(" ") }
  }

  private fun debug(a: IntArray) {
    debug { a.joinToString(" ") }
  }

  private fun debug(a: BooleanArray) {
    debug { a.map { if (it) 1 else 0 }.joinToString("") }
  }

  private fun debugDim(A: Array<LongArray>) {
    if (isDebug) {
      for (a in A) {
        debug(a)
      }
    }
  }
  private fun debugDim(A: Array<IntArray>) {
    if (isDebug) {
      for (a in A) {
        debug(a)
      }
    }
  }

  /**
   * 勝手にimport消されるのを防ぎたい
   */
  private fun hoge() {
    min(1, 2)
    max(1, 2)
    abs(-10)
  }
}

fun main() {
  val out = java.io.PrintWriter(System.out)
  Solver(System.`in`, out).solve()
  out.flush()
}
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