結果

問題 No.1660 Matrix Exponentiation
ユーザー 箱星箱星
提出日時 2021-07-23 08:17:46
言語 Kotlin
(2.1.0)
結果
AC  
実行時間 1,226 ms / 2,000 ms
コード長 2,354 bytes
コンパイル時間 15,844 ms
コンパイル使用メモリ 450,112 KB
実行使用メモリ 135,988 KB
最終ジャッジ日時 2024-06-23 07:08:02
合計ジャッジ時間 33,258 ms
ジャッジサーバーID
(参考情報)
judge5 / judge3
このコードへのチャレンジ
(要ログイン)
ファイルパターン 結果
sample AC * 3
other AC * 27
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 #
プレゼンテーションモードにする

import java.io.PrintWriter
import java.util.*
import kotlin.math.*
fun PrintWriter.solve() {
val n = nextInt()
val m = nextInt()
val adj = Array(n) { mutableListOf<Int>() }
val set = mutableSetOf<Pair<Int, Int>>()
for (i in 0 until m) {
val v1 = nextInt() - 1
val v2 = nextInt() - 1
if (v1 == v2 || set.contains(v2 to v1)) {
println(-1)
return
}
adj[v1].add(v2)
set.add(v1 to v2)
}
if (findCycle(adj).isNotEmpty()) {
println(-1)
} else {
val dp = IntArray(n) { -1 }
fun dfs(v: Int): Int {
if (dp[v] != -1) return dp[v]
var max = 0
for (w in adj[v]) {
max = maxOf(max, dfs(w))
}
dp[v] = max + 1
return dp[v]
}
(0 until n).forEach { dfs(it) }
println(dp.maxOrNull()!!)
}
}
fun findCycle(adj: Array<MutableList<Int>>): List<Int> {
val n = adj.size
val seen = BooleanArray(n) { false }
val finished = BooleanArray(n) { false }
var pos = -1
val hist = Stack<Int>()
fun dfs(v: Int, p: Int) {
seen[v] = true
hist.push(v)
for (w in adj[v]) {
if (w == p) continue
if (finished[w]) continue
if (seen[w] && !finished[w]) {
pos = w
return
}
dfs(w, v)
if (pos != -1) return
}
hist.pop()
finished[v] = true
}
for (i in 0 until n) {
if (!finished[i]) {
dfs(i, -1)
if (pos != -1) break
}
}
val cycle = mutableListOf<Int>()
while (hist.isNotEmpty()) {
val t = hist.pop()
cycle.add(t)
if (t == pos) break
}
return cycle
}
fun main() {
Thread(null, {
val writer = PrintWriter(System.out, false)
writer.solve()
writer.flush()
}, "solve", 1.shl(26)).start()
}
// 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
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
0