結果
| 問題 | No.904 サメトロ |
| コンテスト | |
| ユーザー |
 kakel-san
|
| 提出日時 | 2026-01-18 23:20:38 |
| 言語 | C# (.NET 10.0.101) |
| 結果 |
AC
|
| 実行時間 | 97 ms / 1,000 ms |
| コード長 | 6,162 bytes |
| 記録 | |
| コンパイル時間 | 10,606 ms |
| コンパイル使用メモリ | 168,080 KB |
| 実行使用メモリ | 195,096 KB |
| 最終ジャッジ日時 | 2026-01-18 23:20:53 |
| 合計ジャッジ時間 | 14,122 ms |
|
ジャッジサーバーID （参考情報） |
judge2 / judge5 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 33 |
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 (128 ミリ秒)。 main -> /home/judge/data/code/bin/Release/net10.0/main.dll main -> /home/judge/data/code/bin/Release/net10.0/publish/
ソースコード
using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
using System.Security.Cryptography;
using Microsoft.VisualBasic;
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 n = NN;
var map = NArr(n - 1);
var g = new MaxFlowGraph(n * 2);
var s = n * 2 - 2;
var t = n * 2 - 1;
for (var i = 0; i < n - 1; ++i)
{
g.AddEdge(s, i, map[i][0]);
g.AddEdge(i + n - 1, t, map[i][1]);
for (var j = 0; j < n - 1; ++j)
{
if (i == j) continue;
g.AddEdge(i, j + n - 1, 1_000_000);
}
}
var rest = g.Flow(s, t);
WriteLine(rest + 1);
}
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;
}
}
}