結果

問題 No.1639 最小通信路
コンテスト
ユーザー yakamoto
提出日時 2021-08-06 21:54:31
言語 Kotlin
(2.1.0)
結果
AC  
実行時間 424 ms / 2,000 ms
コード長 4,690 bytes
コンパイル時間 17,236 ms
コンパイル使用メモリ 454,636 KB
実行使用メモリ 59,228 KB
最終ジャッジ日時 2024-09-17 01:52:51
合計ジャッジ時間 34,101 ms
ジャッジサーバーID
（参考情報） 		judge6 / judge4
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 2
other AC * 43
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:185:11: warning: expected performance impact from inlining is insignificant. Inlining works best for functions with parameters of functional types
  private inline fun debug(a: LongArray) {
          ^
Main.kt:189:11: warning: expected performance impact from inlining is insignificant. Inlining works best for functions with parameters of functional types
  private inline fun debug(a: IntArray) {
          ^
Main.kt:193:11: warning: expected performance impact from inlining is insignificant. Inlining works best for functions with parameters of functional types
  private inline fun debug(a: BooleanArray) {
          ^
Main.kt:197:11: warning: expected performance impact from inlining is insignificant. Inlining works best for functions with parameters of functional types
  private inline fun toString(a: BooleanArray) = run{a.map { if (it) 1 else 0 }.joinToString("")}
          ^
Main.kt:199:11: warning: expected performance impact from inlining is insignificant. Inlining works best for functions with parameters of functional types
  private inline fun debugDim(A: Array<LongArray>) {
          ^
Main.kt:206:11: warning: expected performance impact from inlining is insignificant. Inlining works best for functions with parameters of functional types
  private inline fun debugDim(A: Array<IntArray>) {
          ^
Main.kt:213:11: warning: expected performance impact from inlining is insignificant. Inlining works best for functions with parameters of functional types
  private inline fun debugDim(A: Array<BooleanArray>) {
          ^
Main.kt:230:11: warning: expected performance impact from inlining is insignificant. Inlining works best for functions with parameters of functional types
  private inline fun assert(b: Boolean) = run{if (!b) throw AssertionError()}
          ^

ソースコード

diff # 

import java.io.BufferedReader
import java.io.InputStream
import java.io.InputStreamReader
import java.lang.AssertionError
import java.util.*
import kotlin.math.abs
import kotlin.math.max
import kotlin.math.min

val MOD = 1_000_000_007
class UnionFind(n: Int) {
  private val par = IntArray(n){it}
  private val rank = IntArray(n){1} // 集合の要素数
  private val visits = IntArray(n) // 訪れた場所をfind毎に用意するのがもったいないのでつかいまわす

  fun find(x: Int): Int {
    var ptr = 0
    var i = x
    while(par[i] != i) {
      visits[ptr++] = i
      i = par[i]
    }

    for (j in 0 until ptr) {
      par[visits[j]] = i
    }
    return i
  }

  private fun merge(node: Int, rt: Int): Int {
    par[node] = rt
    rank[rt] += rank[node]
    return rt
  }

  fun unite(x: Int, y: Int): Boolean {
    val x1 = find(x)
    val y1 = find(y)
    return if (x1 == y1) false
    else {
      if (rank[x1] < rank[y1])
        merge(x1, y1)
      else
        merge(y1, x1)

      true
    }
  }

  fun isSame(x: Int, y: Int) = find(x) == find(y)

  fun isRoot(x: Int) = par[x] == x

  /**
   * xを解決する必要がないときは直にrankをみる
   */
  fun cntNodes(x: Int): Int = rank[find(x)]

  fun inspect() = run{par}
}
data class Edge(val v: Int, val u: Int, val C: String)
/**
 * 単調増加
 * (l, h] 方式
 * @return マッチするものがなかったらmx
 */
inline fun findMin(mn: Int, mx: Int, f: (Int) -> Boolean): Int {
  var low = mn - 1
  var high = mx
  while(high - low > 1) {
    val m = (low + high) / 2
    if (f(m)) high = m
    else low = m
  }
  return high
}
class Solver(stream: InputStream, private val out: java.io.PrintWriter) {
  private val reader = BufferedReader(InputStreamReader(stream), 32768)

  fun solve() {
    val N = ni()
    val E = Array(N*(N-1)/2){Edge(ni() - 1, ni() - 1, ns())}
    val i = findMin(0, N*(N-1)/2 - 1) { x ->
      val uf = UnionFind(N)
      var cnt = 0
      for (i in 0 .. x) {
        val e = E[i]
        if (uf.unite(e.v, e.u)) cnt++
      }
      cnt == N - 1
    }
    out.println(E[i].C)
  }













































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

  /**
   * コーナーケースでエラー出たりするので、debug(dp[1])のように添え字付きの場合はdebug{}をつかうこと
   */
  private inline fun debug(a: LongArray) {
    debug { a.joinToString(" ") }
  }

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

  private inline fun debug(a: BooleanArray) {
    debug { toString(a) }
  }

  private inline fun toString(a: BooleanArray) = run{a.map { if (it) 1 else 0 }.joinToString("")}

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

  private inline fun assert(b: Boolean) = run{if (!b) throw AssertionError()}
  private inline fun assert(b: Boolean, f: () -> String) = run{if (!b) throw AssertionError(f())}

  companion object {
    // TestRunnerから呼びたいので単純なmainじゃだめ
    fun main() {
      val out = java.io.PrintWriter(System.out)
      Solver(System.`in`, out).solve()
      out.flush()
    }
  }
}

/**
 * judgeから呼ばれる
 */
fun main() = Solver.main()
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