結果

問題 No.2780 The Bottle Imp
ユーザー kakel-sankakel-san
提出日時 2024-06-07 22:22:21
言語 C#
(.NET 8.0.404)
結果
AC  
実行時間 230 ms / 2,000 ms
コード長 5,106 bytes
コンパイル時間 21,937 ms
コンパイル使用メモリ 168,208 KB
実行使用メモリ 190,060 KB
最終ジャッジ日時 2024-12-27 14:03:20
合計ジャッジ時間 15,037 ms
ジャッジサーバーID
(参考情報)
judge2 / judge1
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 * 4
other AC * 40
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
  復元対象のプロジェクトを決定しています...
  /home/judge/data/code/main.csproj を復元しました (152 ms)。
MSBuild のバージョン 17.9.6+a4ecab324 (.NET)
  main -> /home/judge/data/code/bin/Release/net8.0/main.dll
  main -> /home/judge/data/code/bin/Release/net8.0/publish/

ソースコード

diff #
プレゼンテーションモードにする

using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
class Program
{
static int NN => int.Parse(ReadLine());
static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
public static void Main()
{
Solve();
}
static void Solve()
{
var n = NN;
var map = NArr(n);
WriteLine(Bottle(n, map) ? "Yes" : "No");
}
static bool Bottle(int n, int[][] map)
{
var g = new SCCGraph(n);
for (var i = 0; i < n; ++i) for (var j = 1; j < map[i].Length; ++j)
{
g.AddEdge(i, map[i][j] - 1);
}
var scc = g.SCC();
var gid = new int[n];
for (var i = 0; i < scc.Length; ++i) foreach (var s in scc[i]) gid[s] = i;
var tree = new List<int>[scc.Length];
for (var i = 0; i < tree.Length; ++i) tree[i] = new List<int>();
var refs = new int[scc.Length];
for (var i = 0; i < n; ++i) for (var j = 1; j < map[i].Length; ++j)
{
if (gid[i] != gid[map[i][j] - 1])
{
tree[gid[i]].Add(gid[map[i][j] - 1]);
++refs[gid[map[i][j] - 1]];
}
}
if (refs[gid[0]] > 0)
{
return false;
}
var list = new List<int>();
var q = new Queue<int>();
for (var i = 0; i < refs.Length; ++i) if (refs[i] == 0)
{
list.Add(i);
q.Enqueue(i);
}
if (q.Count > 1)
{
return false;
}
while (q.Count > 0)
{
var cur = q.Dequeue();
foreach (var next in tree[cur])
{
--refs[next];
if (refs[next] == 0)
{
list.Add(next);
q.Enqueue(next);
if (q.Count > 1)
{
return false;
}
}
}
}
return list.Count == scc.Length;
}
class SCCGraph
{
private int _n;
private List<(int from, int to)> edges;
public SCCGraph(int n)
{
_n = n;
edges = new List<(int, int)>();
}
public int NumVertices() { return _n; }
public void AddEdge(int from, int to) { edges.Add((from, to )); }
public (int, int[]) SCCIds()
{
var g = new CSR<int>(_n, edges);
var nowOrd = 0;
var groupNum = 0;
var visited = new List<int>(_n);
var low = new int[_n];
var ord = Enumerable.Repeat(-1, _n).ToArray();
var ids = new int[_n];
void DFS(int v)
{
low[v] = ord[v] = nowOrd++;
visited.Add(v);
for (var i = g.Start[v]; i < g.Start[v + 1]; ++i)
{
var to = g.EList[i];
if (ord[to] == -1)
{
DFS(to);
low[v] = Math.Min(low[v], low[to]);
}
else low[v] = Math.Min(low[v], ord[to]);
}
if (low[v] == ord[v])
{
while (true)
{
var u = visited.Last();
visited.RemoveAt(visited.Count - 1);
ord[u] = _n;
ids[u] = groupNum;
if (u == v) break;
}
++groupNum;
}
}
for (var i = 0; i < _n; ++i) if (ord[i] == -1) DFS(i);
for (var i = 0; i < ids.Length; ++i) ids[i] = groupNum - 1 - ids[i];
return (groupNum, ids);
}
public List<int>[] SCC()
{
var (groupNum, list) = SCCIds();
var counts = new int[groupNum];
foreach (var x in list) ++counts[x];
var groups = new List<int>[groupNum];
for (var i = 0; i < groups.Length; ++i) groups[i] = new List<int>(counts[i]);
for (var i = 0; i < _n; ++i) groups[list[i]].Add(i);
return groups;
}
}
//
class CSR<E>
{
public int[] Start { get; private set; }
public E[] EList { get; private set; }
public CSR(int n, List<(int, E)> edges)
{
Start = new int[n + 1];
EList = new E[edges.Count];
foreach (var e in edges) ++Start[e.Item1 + 1];
for (var i = 1; i <= n; ++i) Start[i] += Start[i - 1];
var counter = (int[])Start.Clone();
foreach (var e in edges)
{
EList[counter[e.Item1]++] = e.Item2;
}
}
}
}
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