結果
問題 | No.1507 Road Blocked |
ユーザー |
![]() |
提出日時 | 2021-05-14 22:35:09 |
言語 | Kotlin (2.1.0) |
結果 |
AC
|
実行時間 | 582 ms / 2,000 ms |
コード長 | 5,012 bytes |
コンパイル時間 | 18,662 ms |
コンパイル使用メモリ | 473,576 KB |
実行使用メモリ | 79,108 KB |
最終ジャッジ日時 | 2024-10-02 02:27:38 |
合計ジャッジ時間 | 35,447 ms |
ジャッジサーバーID (参考情報) |
judge3 / judge1 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 30 |
コンパイルメッセージ
Main.kt:95:9: warning: the value 'u' assigned to 'var v: Int defined in Solver.solve' is never used v = u ^ Main.kt:200:11: 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:204:11: 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:208:11: 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:212:11: 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:214:11: 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:221:11: 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:228:11: 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:245:11: 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
import java.io.BufferedReaderimport java.io.InputStreamimport java.io.InputStreamReaderimport java.lang.AssertionErrorimport java.util.*import kotlin.math.absimport kotlin.math.maximport kotlin.math.minval MOD = 998_244_353fun packUGraph(n: Int, from: IntArray, to: IntArray): Array<IntArray> {val p = IntArray(n)val m = from.sizefor (i in 0 until m) {++p[from[i]]++p[to[i]]}val g = Array(n){IntArray(p[it])}for (i in 0 until m) {g[from[i]][--p[from[i]]] = to[i]g[to[i]][--p[to[i]]] = from[i]}return g}/*** (dist, parent, queue)* @param rt ルートノードを指定する。nullの場合は全ノード辿るまで繰り返す*/fun traceBfs(g: Array<IntArray>, rt: Int? = 0): Array<IntArray> {val n = g.sizeval q = IntArray(n)val d = IntArray(n)val p = IntArray(n){-2}var h = 0var t = 0fun bfs(rt: Int) {p[rt] = -1q[t++] = rtd[rt] = 0while (h < t) {val v = q[h++]for (i in g[v].indices) { // List<Int>に変更したときこちらの方法でないとiterator生成して遅くなるval u = g[v][i]if (p[u] == -2) {p[u] = vq[t++] = ud[u] = d[v] + 1}}}}if (rt != null) {bfs(rt)} else {for (v in 0 until n) {if (p[v] != -2) continuebfs(v)}}return arrayOf(d, p, q)}fun powMod(a: Long, n: Long, mod: Int): Long {if (n == 0L) return 1val res = powMod(a * a % mod, n / 2, mod)return if (n % 2 == 1L) res * a % mod else res}class Solver(stream: InputStream, private val out: java.io.PrintWriter) {private val reader = BufferedReader(InputStreamReader(stream), 32768)fun solve() {val N = ni()val (from, to) = na2(N - 1, -1)val g = packUGraph(N, from, to)val (_, par, que) = traceBfs(g)val dp = LongArray(N)for (i in N - 1 downTo 0) {val v = que[i]dp[v]++for (u in g[v]) {if (u == par[v]) continuedp[v] += dp[u]}}debug(dp)var cnt = 0Lfor (i in 0 until N - 1) {var v = from[i] // 親var u = to[i]if (par[v] == u) {val t = vv = uu = t}val n = dp[u] // 子供側val m = N - ncnt = (cnt + n*(n - 1)/2 + m*(m - 1)/2)%MOD// debug{"$n $m $cnt"}}debug{"$cnt"}val invn1 = powMod(N.toLong()-1, MOD.toLong()-2, MOD)val invn = powMod(N.toLong(), MOD.toLong()-2, MOD)val ans = cnt *invn1% MOD *invn%MOD *invn1%MOD *2%MOD // q = (n-1)*n*(n-1)/2out.println(ans)}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? = nullprivate 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())}}fun main() {val out = java.io.PrintWriter(System.out)Solver(System.`in`, out).solve()out.flush()}