#1182683 (C++23) No.3668 Minimum Cut

• 問題: No.3668 Minimum Cut
• ユーザー: HoyHoyCharhang
• 提出日時: 2026-09-04 23:48:23
• 言語: C++23 (gcc 15.3.0 + boost 1.92.0)
• 結果: TLE
• 実行時間: -
• コード長: 3,083 bytes
• コンパイル時間: 2,352 ms
• コンパイル使用メモリ: 345,456 KB
• 実行使用メモリ: 6,272 KB
• 最終ジャッジ日時: 2026-09-04 23:48:31
• 合計ジャッジ時間: 7,231 ms
• ジャッジサーバーID （参考情報）: judge3_0 / judge2_0

ファイルパターン	結果
sample	AC * 3
other	AC * 21 TLE * 1 -- * 17

ソースコード

#include <bits/stdc++.h>
#define fi first
#define se second
#define rep(i,s,n) for (int i = (s); i < (n); ++i)
#define rrep(i,g,n) for (int i = (n)-1; i >= (g); --i)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define len(x) (int)(x).size()
#define dup(x,y) (((x)+(y)-1)/(y))
#define pb push_back
#define eb emplace_back
#define Field(T) vector<vector<T>>
using namespace std;
using ll = long long;
using ull = unsigned long long;
template<typename T> using pq = priority_queue<T,vector<T>,greater<T>>;
using P = pair<int,int>;
template<class T>bool chmax(T&a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T&a,T b){if(b<a){a=b;return 1;}return 0;}

template <typename T>
struct MaxFlow {
  struct edge {
    int to;
    T cap;
    int rev;
    bool is_rev;
  };

  vector<vector<edge>> G;
  vector<int> dist, iter;

  MaxFlow() = default;
  explicit MaxFlow(int n) : G(n) {}

  void add_edge(int from, int to, T cap = 1) {
    G[from].emplace_back(edge{to, cap, (int)G[to].size(), 0});
    G[to].emplace_back(edge{from, 0, (int)G[from].size()-1, 1});
  }

  void debug() {
    for (int i = 0; i < (int)G.size(); ++i) {
      for (edge &e : G[i]) {
        if (e.is_rev) continue;
        edge &rev_e = G[e.to][e.rev];
        cout << i << " -> " << e.to << " : " << "(" << rev_e.cap << "/" << e.cap + rev_e.cap << ")" << endl;
      }
    }
  }

  void bfs(const int &s) {
    dist.assign(G.size(), -1);
    dist[s] = 0;
    queue<int> que;
    que.push(s);
    while(!que.empty()) {
      int v = que.front();
      que.pop();
      for (edge &e : G[v]) {
        if (e.cap == 0 || dist[e.to] >= 0) continue;
        dist[e.to] = dist[v] + 1;
        que.push(e.to);
      }
    }
  }

  T dfs(int v, const int &t, T f) {
    if (v == t) return f;
    T ret = 0;
    for (int& i = iter[v]; i < (int)G[v].size(); ++i) {
      edge& e = G[v][i];
      if (e.cap == 0 || dist[v] >= dist[e.to]) continue;
      T d = dfs(e.to, t, min(f - ret, e.cap));
      if (d == 0) continue;
      e.cap -= d;
      G[e.to][e.rev].cap += d;
      ret += d;
      if (f == ret) break;
    }
    return ret;
  }

  T flow(int s, int t, T f_limit = numeric_limits<T>::max()) {
    T ret = 0;
    queue<int> que;
    while(true) {
      bfs(s);
      if (dist[t] == -1) break;
      iter.assign(G.size(), 0);
      while(ret < f_limit) {
        T f = dfs(s, t, f_limit - ret);
        if (f == 0) break;
        ret += f;
      }
    }
    return ret;
  }

  vector<bool> min_cut(int s) {
    vector<bool> used(G.size(), 0);
    used[s] = 1;
    queue<int> que;
    que.push(s);
    while(!que.empty()) {
      int v = que.front();
      que.pop();
      for (edge &e : G[v]) {
        if (e.cap > 0 && !used[e.to]) {
          used[e.to] = 1;
          que.push(e.to);
        }
      }
    }
    return used;
  }
};

int main() {
  int n, m, s, t;
  cin >> n >> m >> s >> t;
  --s, --t;
  MaxFlow<ll> mf(n);
  rep(i,0,m) {
    int u, v, c;
    cin >> u >> v >> c;
    --u, --v;
    mf.add_edge(u, v, c);
  }
  cout << mf.flow(s, t) << endl;
  return 0;
}