結果

問題 No.1301 Strange Graph Shortest Path
ユーザー 👑 emthrmemthrm
提出日時 2020-11-27 23:51:43
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 213 ms / 3,000 ms
コード長 4,932 bytes
コンパイル時間 2,567 ms
コンパイル使用メモリ 217,716 KB
実行使用メモリ 34,580 KB
最終ジャッジ日時 2024-07-26 20:11:31
合計ジャッジ時間 10,186 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge3
このコードへのチャレンジ
（要ログイン）

テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 2 ms
6,816 KB
testcase_01 AC 2 ms
6,944 KB
testcase_02 AC 155 ms
32,508 KB
testcase_03 AC 128 ms
29,056 KB
testcase_04 AC 203 ms
31,488 KB
testcase_05 AC 129 ms
32,000 KB
testcase_06 AC 178 ms
29,312 KB
testcase_07 AC 163 ms
30,464 KB
testcase_08 AC 126 ms
29,436 KB
testcase_09 AC 168 ms
27,904 KB
testcase_10 AC 132 ms
29,056 KB
testcase_11 AC 184 ms
30,208 KB
testcase_12 AC 188 ms
30,080 KB
testcase_13 AC 166 ms
32,680 KB
testcase_14 AC 164 ms
27,904 KB
testcase_15 AC 162 ms
28,724 KB
testcase_16 AC 207 ms
31,488 KB
testcase_17 AC 176 ms
33,032 KB
testcase_18 AC 152 ms
29,940 KB
testcase_19 AC 184 ms
29,312 KB
testcase_20 AC 187 ms
28,416 KB
testcase_21 AC 166 ms
31,612 KB
testcase_22 AC 193 ms
29,312 KB
testcase_23 AC 162 ms
32,396 KB
testcase_24 AC 185 ms
29,184 KB
testcase_25 AC 200 ms
31,360 KB
testcase_26 AC 172 ms
30,080 KB
testcase_27 AC 179 ms
30,208 KB
testcase_28 AC 140 ms
31,912 KB
testcase_29 AC 213 ms
30,720 KB
testcase_30 AC 194 ms
31,232 KB
testcase_31 AC 199 ms
30,972 KB
testcase_32 AC 2 ms
6,940 KB
testcase_33 AC 82 ms
25,344 KB
testcase_34 AC 190 ms
34,580 KB
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 # 

#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
constexpr int dy8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dx8[] = {0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

template <typename T, typename U>
struct PrimalDual {
  struct Edge {
    int dst, rev;
    T cap;
    U cost;
    Edge(int dst, T cap, U cost, int rev) : dst(dst), cap(cap), cost(cost), rev(rev) {}
  };

  std::vector<std::vector<Edge>> graph;

  PrimalDual(int n, const T TINF, const U UINF) : n(n), TINF(TINF), UINF(UINF), graph(n), prev_v(n, -1), prev_e(n, -1), potential(n, 0), dist(n) {}

  void add_edge(int src, int dst, T cap, U cost) {
    has_negative_edge |= cost < 0;
    graph[src].emplace_back(dst, cap, cost, graph[dst].size());
    graph[dst].emplace_back(src, 0, -cost, graph[src].size() - 1);
  }

  U minimum_cost_flow(int s, int t, T flow) {
    U res = 0;
    if (has_negative_edge) {
      bellman_ford(s);
      if (dist[t] == UINF) return UINF;
      res += calc(s, t, flow);
    }
    while (flow > 0) {
      dijkstra(s);
      if (dist[t] == UINF) return UINF;
      res += calc(s, t, flow);
    }
    return res;
  }

  U minimum_cost_flow(int s, int t) {
    U res = 0;
    bellman_ford(s);
    if (potential[t] >= 0 || dist[t] == UINF) return res;
    T tmp = TINF;
    res += calc(s, t, tmp);
    while (true) {
      dijkstra(s);
      if (potential[t] >= 0 || dist[t] == UINF) return res;
      res += calc(s, t, tmp);
    }
  }

  std::pair<T, U> min_cost_max_flow(int s, int t, T flow) {
    T mx = flow;
    U cost = 0;
    if (has_negative_edge) {
      bellman_ford(s);
      if (dist[t] == UINF) return {mx - flow, cost};
      cost += calc(s, t, flow);
    }
    while (flow > 0) {
      dijkstra(s);
      if (dist[t] == UINF) return {mx - flow, cost};
      cost += calc(s, t, flow);
    }
    return {mx - flow, cost};
  }

private:
  using Pui = std::pair<U, int>;

  int n;
  const T TINF;
  const U UINF;
  bool has_negative_edge = false;
  std::vector<int> prev_v, prev_e;
  std::vector<U> potential, dist;
  std::priority_queue<Pui, std::vector<Pui>, std::greater<Pui>> que;

  void bellman_ford(int s) {
    std::fill(dist.begin(), dist.end(), UINF);
    dist[s] = 0;
    bool is_updated = true;
    for (int step = 0; step < n; ++step) {
      is_updated = false;
      for (int i = 0; i < n; ++i) {
        if (dist[i] == UINF) continue;
        for (int j = 0; j < graph[i].size(); ++j) {
          Edge e = graph[i][j];
          if (e.cap > 0 && dist[e.dst] > dist[i] + e.cost) {
            dist[e.dst] = dist[i] + e.cost;
            prev_v[e.dst] = i;
            prev_e[e.dst] = j;
            is_updated = true;
          }
        }
      }
      if (!is_updated) break;
    }
    assert(!is_updated);
    for (int i = 0; i < n; ++i) {
      if (dist[i] != UINF) potential[i] += dist[i];
    }
  }

  void dijkstra(int s) {
    std::fill(dist.begin(), dist.end(), UINF);
    dist[s] = 0;
    que.emplace(0, s);
    while (!que.empty()) {
      Pui pr = que.top(); que.pop();
      int ver = pr.second;
      if (dist[ver] < pr.first) continue;
      for (int i = 0; i < graph[ver].size(); ++i) {
        Edge e = graph[ver][i];
        U nx = dist[ver] + e.cost + potential[ver] - potential[e.dst];
        if (e.cap > 0 && dist[e.dst] > nx) {
          dist[e.dst] = nx;
          prev_v[e.dst] = ver;
          prev_e[e.dst] = i;
          que.emplace(dist[e.dst], e.dst);
        }
      }
    }
    for (int i = 0; i < n; ++i) {
      if (dist[i] != UINF) potential[i] += dist[i];
    }
  }

  U calc(int s, int t, T &flow) {
    T f = flow;
    for (int v = t; v != s; v = prev_v[v]) f = std::min(f, graph[prev_v[v]][prev_e[v]].cap);
    flow -= f;
    for (int v = t; v != s; v = prev_v[v]) {
      Edge &e = graph[prev_v[v]][prev_e[v]];
      e.cap -= f;
      graph[v][e.rev].cap += f;
    }
    return potential[t] * f;
  }
};

int main() {
  int n, m; cin >> n >> m;
  PrimalDual<int, ll> pd(n, INF, LINF);
  while (m--) {
    int u, v, c, d; cin >> u >> v >> c >> d; --u; --v;
    pd.add_edge(u, v, 1, c);
    pd.add_edge(v, u, 1, c);
    pd.add_edge(u, v, 1, d);
    pd.add_edge(v, u, 1, d);
  }
  cout << pd.minimum_cost_flow(0, n - 1, 2) << '\n';
  return 0;
}
0