結果

問題 No.2286 Join Hands
ユーザー t98slidert98slider
提出日時 2023-04-28 23:07:16
言語 C++14
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 1,050 ms / 2,000 ms
コード長 5,805 bytes
コンパイル時間 2,202 ms
コンパイル使用メモリ 191,484 KB
実行使用メモリ 11,488 KB
最終ジャッジ日時 2024-04-29 00:23:47
合計ジャッジ時間 25,318 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge1
このコードへのチャレンジ
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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
5,248 KB
testcase_01 AC 2 ms
5,376 KB
testcase_02 AC 2 ms
5,376 KB
testcase_03 AC 2 ms
5,376 KB
testcase_04 AC 2 ms
5,376 KB
testcase_05 AC 2 ms
5,376 KB
testcase_06 AC 2 ms
5,376 KB
testcase_07 AC 2 ms
5,376 KB
testcase_08 AC 63 ms
5,632 KB
testcase_09 AC 82 ms
5,632 KB
testcase_10 AC 346 ms
8,064 KB
testcase_11 AC 459 ms
9,144 KB
testcase_12 AC 467 ms
8,936 KB
testcase_13 AC 315 ms
7,744 KB
testcase_14 AC 667 ms
10,064 KB
testcase_15 AC 587 ms
9,776 KB
testcase_16 AC 700 ms
10,448 KB
testcase_17 AC 54 ms
5,376 KB
testcase_18 AC 885 ms
10,976 KB
testcase_19 AC 1,023 ms
10,772 KB
testcase_20 AC 1,048 ms
10,816 KB
testcase_21 AC 861 ms
11,096 KB
testcase_22 AC 1,050 ms
10,796 KB
testcase_23 AC 938 ms
10,616 KB
testcase_24 AC 986 ms
11,076 KB
testcase_25 AC 1,004 ms
10,628 KB
testcase_26 AC 1,003 ms
10,616 KB
testcase_27 AC 966 ms
10,632 KB
testcase_28 AC 2 ms
5,376 KB
testcase_29 AC 2 ms
5,376 KB
testcase_30 AC 2 ms
5,376 KB
testcase_31 AC 2 ms
5,376 KB
testcase_32 AC 2 ms
5,376 KB
testcase_33 AC 2 ms
5,376 KB
testcase_34 AC 2 ms
5,376 KB
testcase_35 AC 2 ms
5,376 KB
testcase_36 AC 2 ms
5,376 KB
testcase_37 AC 2 ms
5,376 KB
testcase_38 AC 2 ms
5,376 KB
testcase_39 AC 2 ms
5,376 KB
testcase_40 AC 2 ms
5,376 KB
testcase_41 AC 2 ms
5,376 KB
testcase_42 AC 2 ms
5,376 KB
testcase_43 AC 2 ms
5,376 KB
testcase_44 AC 2 ms
5,376 KB
testcase_45 AC 2 ms
5,376 KB
testcase_46 AC 2 ms
5,376 KB
testcase_47 AC 677 ms
11,488 KB
testcase_48 AC 676 ms
11,476 KB
testcase_49 AC 674 ms
11,352 KB
testcase_50 AC 674 ms
11,484 KB
testcase_51 AC 462 ms
10,588 KB
testcase_52 AC 131 ms
6,912 KB
testcase_53 AC 709 ms
11,480 KB
testcase_54 AC 254 ms
7,548 KB
testcase_55 AC 361 ms
9,048 KB
testcase_56 AC 673 ms
11,348 KB
testcase_57 AC 681 ms
11,356 KB
testcase_58 AC 682 ms
11,480 KB
testcase_59 AC 681 ms
11,360 KB
testcase_60 AC 472 ms
10,916 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 # 

#include <bits/stdc++.h>
using namespace std;
using ll = long long;


template <class Cap, class Cost> struct mcf_graph {
  public:
    mcf_graph() {}
    mcf_graph(int n) : _n(n), g(n) {}
    int add_edge(int from, int to, Cap cap, Cost cost) {
        assert(0 <= from && from < _n);
        assert(0 <= to && to < _n);
        int m = int(pos.size());
        pos.push_back({from, int(g[from].size())});
        g[from].push_back(_edge{to, int(g[to].size()), cap, cost});
        g[to].push_back(_edge{from, int(g[from].size()) - 1, 0, -cost});
        return m;
    }
    struct edge {
        int from, to;
        Cap cap, flow;
        Cost cost;
    };
    edge get_edge(int i) {
        int m = int(pos.size());
        assert(0 <= i && i < m);
        auto _e = g[pos[i].first][pos[i].second];
        auto _re = g[_e.to][_e.rev];
        return edge{
            pos[i].first, _e.to, _e.cap + _re.cap, _re.cap, _e.cost,
        };
    }
    std::vector<edge> edges() {
        int m = int(pos.size());
        std::vector<edge> result(m);
        for (int i = 0; i < m; i++) {
            result[i] = get_edge(i);
        }
        return result;
    }
    std::pair<Cap, Cost> flow(int s, int t) {
        return flow(s, t, std::numeric_limits<Cap>::max());
    }
    std::pair<Cap, Cost> flow(int s, int t, Cap flow_limit) {
        return slope(s, t, flow_limit).back();
    }
    std::vector<std::pair<Cap, Cost>> slope(int s, int t) {
        return slope(s, t, std::numeric_limits<Cap>::max());
    }
    std::vector<std::pair<Cap, Cost>> slope(int s, int t, Cap flow_limit) {
        assert(0 <= s && s < _n);
        assert(0 <= t && t < _n);
        assert(s != t);
        std::vector<Cost> dual(_n, 0), dist(_n);
        std::vector<int> pv(_n), pe(_n);
        std::vector<bool> vis(_n);
        auto dual_ref = [&]() {
            std::fill(dist.begin(), dist.end(),
                      std::numeric_limits<Cost>::max());
            std::fill(pv.begin(), pv.end(), -1);
            std::fill(pe.begin(), pe.end(), -1);
            std::fill(vis.begin(), vis.end(), false);
            struct Q {
                Cost key;
                int to;
                bool operator<(Q r) const { return key > r.key; }
            };
            std::priority_queue<Q> que;
            dist[s] = 0;
            que.push(Q{0, s});
            while (!que.empty()) {
                int v = que.top().to;
                que.pop();
                if (vis[v]) continue;
                vis[v] = true;
                if (v == t) break;
                for (int i = 0; i < int(g[v].size()); i++) {
                    auto e = g[v][i];
                    if (vis[e.to] || !e.cap) continue;
                    Cost cost = e.cost - dual[e.to] + dual[v];
                    if (dist[e.to] - dist[v] > cost) {
                        dist[e.to] = dist[v] + cost;
                        pv[e.to] = v;
                        pe[e.to] = i;
                        que.push(Q{dist[e.to], e.to});
                    }
                }
            }
            if (!vis[t]) {
                return false;
            }
            for (int v = 0; v < _n; v++) {
                if (!vis[v]) continue;
                dual[v] -= dist[t] - dist[v];
            }
            return true;
        };
        Cap flow = 0;
        Cost cost = 0, prev_cost = -1;
        std::vector<std::pair<Cap, Cost>> result;
        result.push_back({flow, cost});
        while (flow < flow_limit) {
            if (!dual_ref()) break;
            Cap c = flow_limit - flow;
            for (int v = t; v != s; v = pv[v]) {
                c = std::min(c, g[pv[v]][pe[v]].cap);
            }
            for (int v = t; v != s; v = pv[v]) {
                auto& e = g[pv[v]][pe[v]];
                e.cap -= c;
                g[v][e.rev].cap += c;
            }
            Cost d = -dual[s];
            flow += c;
            cost += c * d;
            if (prev_cost == d) {
                result.pop_back();
            }
            result.push_back({flow, cost});
            prev_cost = cost;
        }
        return result;
    }
    std::vector<Cost> detail_slope(int s, int t){
        std::vector<std::pair<Cap, Cost>> ori = slope(s, t);
        std::vector<Cost> ans(ori.back().first + 1);
        Cap x = 0, nx;
        Cost y = 0, ny;
        for(int i = 1; i < ori.size(); i++){
            std::tie(nx, ny) = ori[i];
            Cost d = (ny - y) / (nx - x);
            while(x != nx){
                ++x, y+= d;
                ans[x] = y;
            }
        }
        return ans;
    }

  private:
    int _n;
    struct _edge {
        int to, rev;
        Cap cap;
        Cost cost;
    };
    std::vector<std::pair<int, int>> pos;
    std::vector<std::vector<_edge>> g;
};

int main(){
	ios::sync_with_stdio(false);
    cin.tie(0);
    int n, m, u, v;
    cin >> n >> m;
    ll INF = 1ll << 30;
    mcf_graph<int, ll> g(4 * n + 2);
    vector<vector<bool>> A(n, vector<bool>(n));
    int s = 4 * n, t = s + 1;
    for(int i = 0; i < m; i++){
        cin >> u >> v;
        u--, v--;
        A[u][v] = A[v][u] = true;
        g.add_edge(v, u + 3 * n, 2, 0);
        g.add_edge(u, v + 3 * n, 2, 0);
    }
    for(int i = 0; i < n; i++){
        g.add_edge(s, i, 2, 0);

        g.add_edge(i + n, i + 3 * n, 2, 0);
        g.add_edge(i + 2 * n, i + 3 * n, 2, 0);

        g.add_edge(i + 3 * n, t, 2, 0);

        if(i >= 1){
            g.add_edge(i + n, i + n - 1, INF, 0);
            g.add_edge(i, i + n - 1, 2, INF);
        }

        if(i + 1 < n){
            g.add_edge(i + 2 * n, i + 2 * n + 1, INF, 0);
            g.add_edge(i, i + 2 * n + 1, 2, INF);
        }
    }
    auto p = g.flow(s, t);
    //cerr << p.first << '\n';
    cout << n - p.second / INF << '\n';
}
0