結果
| 問題 |
No.3024 全単射的
|
| ユーザー |
 kakel-san
|
| 提出日時 | 2025-02-23 17:08:00 |
| 言語 | C# (.NET 8.0.404) |
| 結果 |
AC
|
| 実行時間 | 1,099 ms / 5,000 ms |
| コード長 | 7,008 bytes |
| コンパイル時間 | 9,676 ms |
| コンパイル使用メモリ | 175,064 KB |
| 実行使用メモリ | 296,668 KB |
| 最終ジャッジ日時 | 2025-02-23 17:08:18 |
| 合計ジャッジ時間 | 18,037 ms |
|
ジャッジサーバーID （参考情報） |
judge5 / judge2 |
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| ファイルパターン | 結果 |
|---|---|
| other | AC * 22 |
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 (94 ミリ秒)。 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
using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
class Program
{
static int NN => int.Parse(ReadLine());
static long[] NList => ReadLine().Split().Select(long.Parse).ToArray();
static long[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
public static void Main()
{
Solve();
}
static void Solve()
{
var c = NList;
var (n, m) = ((int)c[0], c[1]);
var map = NArr(n);
var set = new HashSet<long>();
for (var i = 0; i < n; ++i)
{
set.Add(map[i][0]);
set.Add(map[i][1]);
}
var list = new List<long>(set);
list.Sort();
var dic = new Dictionary<long, int>();
for (var i = 0; i < list.Count; ++i) dic[list[i]] = i + n;
for (var i = 0; i < n; ++i)
{
map[i][0] = dic[map[i][0]];
map[i][1] = dic[map[i][1]];
}
var s = n + list.Count;
var t = s + 1;
var g = new MaxFlowGraph(t + 1);
for (var i = 0; i < n; ++i)
{
g.AddEdge(s, i, 1);
g.AddEdge(i, (int)map[i][0], 1);
g.AddEdge(i, (int)map[i][1], 1);
}
for (var i = 0; i < list.Count; ++i) g.AddEdge(i + n, t, 1);
WriteLine(g.Flow(s, t));
}
// 最大フローグラフ
// MaxFlowGraph(n) n:頂点数
// AddEdge(from, to, cap) from,to:0-indexed cap:最大用量
// Flow(from, to) 最大流量を求める 各辺の流量を変更
// Flow(from, to, flowLimit)
// MinCut(from) Flow(最小カット)実行後の残余グラフで各頂点への到達可能性を取得
// GetEdge(i), GetEdges() 内部の辺の状態を取得
// ChangeEdge(i, newCap, newFlow) 対象辺の流量を変更
class MaxFlowGraph
{
int _n;
long max = long.MaxValue;
class EdgeI
{
public int to { get; private set; }
public int rev { get; private set; }
public long cap { get; set; }
public EdgeI(int to, int rev, long cap)
{
this.to = to;
this.rev = rev;
this.cap = cap;
}
}
List<KeyValuePair<int, int>> pos = new List<KeyValuePair<int, int>>();
List<EdgeI>[] g;
public MaxFlowGraph(int n)
{
_n = n;
g = new List<EdgeI>[n];
for (var i = 0; i < n; ++i) g[i] = new List<EdgeI>();
}
public int AddEdge(int from, int to, long cap)
{
var m = pos.Count;
pos.Add(new KeyValuePair<int, int>(from, g[from].Count));
g[from].Add(new EdgeI(to, g[to].Count, cap));
g[to].Add(new EdgeI(from, g[from].Count - 1, 0));
return m;
}
public class Edge
{
public int from { get; private set; }
public int to { get; private set; }
public long cap { get; private set; }
public long flow { get; private set; }
public Edge(int from, int to, long cap, long flow)
{
this.from = from;
this.to = to;
this.cap = cap;
this.flow = flow;
}
}
public Edge GetEdge(int i)
{
var m = pos.Count;
var e = g[pos[i].Key][pos[i].Value];
var re = g[e.to][e.rev];
return new Edge(pos[i].Key, e.to, e.cap + re.cap, re.cap);
}
public List<Edge> GetEdges()
{
var m = pos.Count;
var result = new List<Edge>();
for (var i = 0; i < m; ++i) result.Add(GetEdge(i));
return result;
}
public void ChangeEdge(int i, long new_cap, long new_flow)
{
var m = pos.Count;
var e = g[pos[i].Key][pos[i].Value];
var re = g[e.to][e.rev];
e.cap = new_cap - new_flow;
re.cap = new_flow;
}
public long Flow(int s, int t)
{
return Flow(s, t, max);
}
public long Flow(int s, int t, long limit)
{
var level = new int[_n];
var iter = new int[_n];
var que = new Queue<int>();
void bfs()
{
for (var i = 0; i < _n; ++i) level[i] = -1;
level[s] = 0;
que.Clear();
que.Enqueue(s);
while (que.Count > 0)
{
var v = que.Dequeue();
foreach (var e in g[v])
{
if (e.cap == 0 || level[e.to] >= 0) continue;
level[e.to] = level[v] + 1;
if (e.to == t) return;
que.Enqueue(e.to);
}
}
}
long dfs(int v, long up)
{
if (v == s) return up;
long res = 0;
var level_v = level[v];
for (var i = iter[v]; i < g[v].Count; ++i)
{
var e = g[v][i];
if (level_v <= level[e.to] || g[e.to][e.rev].cap == 0) continue;
long d = dfs(e.to, Min(up - res, g[e.to][e.rev].cap));
if (d <= 0) continue;
g[v][i].cap += d;
g[e.to][e.rev].cap -= d;
res += d;
if (res == up) break;
}
return res;
}
long flow = 0;
while (flow < limit)
{
bfs();
if (level[t] == -1) break;
for (var i = 0; i < iter.Length; ++i) iter[i] = 0;
while (flow < limit)
{
var f = dfs(t, limit - flow);
if (f == 0) break;
flow += f;
}
}
return flow;
}
long Min(long a, long b)
{
return a.CompareTo(b) < 0 ? a : b;
}
public bool[] MinCut(int s)
{
var visited = new bool[_n];
var que = new Queue<int>();
que.Enqueue(s);
while (que.Count > 0)
{
var p = que.Dequeue();
visited[p] = true;
foreach (var e in g[p])
{
if (e.cap != 0 && !visited[e.to])
{
visited[e.to] = true;
que.Enqueue(e.to);
}
}
}
return visited;
}
}
}