#863836 (C++17) No.2286 Join Hands

提出ソース

結果

問題	No.2286 Join Hands
ユーザー	Rubikun
提出日時	2023-04-28 22:13:53
言語	C++17 (gcc 12.3.0 + boost 1.83.0)
結果	AC
実行時間	969 ms / 2,000 ms
コード長	12,581 bytes
コンパイル時間	2,566 ms
コンパイル使用メモリ	222,560 KB
実行使用メモリ	8,324 KB
最終ジャッジ日時	2024-11-17 21:10:04
合計ジャッジ時間	19,330 ms
ジャッジサーバーID （参考情報）	judge2 / judge5

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	1 ms 5,248 KB
testcase_02	AC	2 ms 5,248 KB
testcase_03	AC	1 ms 5,248 KB
testcase_04	AC	2 ms 5,248 KB
testcase_05	AC	2 ms 5,248 KB
testcase_06	AC	1 ms 5,248 KB
testcase_07	AC	2 ms 5,248 KB
testcase_08	AC	45 ms 5,376 KB
testcase_09	AC	59 ms 5,504 KB
testcase_10	AC	305 ms 6,492 KB
testcase_11	AC	409 ms 6,948 KB
testcase_12	AC	395 ms 6,956 KB
testcase_13	AC	277 ms 6,476 KB
testcase_14	AC	528 ms 7,504 KB
testcase_15	AC	461 ms 7,232 KB
testcase_16	AC	535 ms 7,640 KB
testcase_17	AC	41 ms 5,504 KB
testcase_18	AC	708 ms 7,688 KB
testcase_19	AC	864 ms 7,428 KB
testcase_20	AC	624 ms 7,556 KB
testcase_21	AC	695 ms 7,676 KB
testcase_22	AC	697 ms 7,304 KB
testcase_23	AC	937 ms 7,432 KB
testcase_24	AC	673 ms 7,556 KB
testcase_25	AC	900 ms 7,296 KB
testcase_26	AC	969 ms 7,460 KB
testcase_27	AC	938 ms 7,168 KB
testcase_28	AC	2 ms 5,248 KB
testcase_29	AC	1 ms 5,248 KB
testcase_30	AC	2 ms 5,248 KB
testcase_31	AC	1 ms 5,248 KB
testcase_32	AC	2 ms 5,248 KB
testcase_33	AC	2 ms 5,248 KB
testcase_34	AC	1 ms 5,248 KB
testcase_35	AC	2 ms 5,248 KB
testcase_36	AC	1 ms 5,248 KB
testcase_37	AC	1 ms 5,248 KB
testcase_38	AC	1 ms 5,248 KB
testcase_39	AC	1 ms 5,248 KB
testcase_40	AC	1 ms 5,248 KB
testcase_41	AC	2 ms 5,248 KB
testcase_42	AC	1 ms 5,248 KB
testcase_43	AC	2 ms 5,248 KB
testcase_44	AC	1 ms 5,248 KB
testcase_45	AC	1 ms 5,248 KB
testcase_46	AC	1 ms 5,248 KB
testcase_47	AC	370 ms 8,196 KB
testcase_48	AC	371 ms 8,324 KB
testcase_49	AC	377 ms 8,196 KB
testcase_50	AC	380 ms 8,200 KB
testcase_51	AC	374 ms 7,164 KB
testcase_52	AC	155 ms 6,272 KB
testcase_53	AC	383 ms 8,196 KB
testcase_54	AC	155 ms 6,236 KB
testcase_55	AC	220 ms 7,056 KB
testcase_56	AC	376 ms 8,244 KB
testcase_57	AC	374 ms 8,196 KB
testcase_58	AC	371 ms 8,200 KB
testcase_59	AC	376 ms 8,196 KB
testcase_60	AC	581 ms 7,556 KB

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ソースコード

raw source code

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return true; } return false; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return true; } return false; }
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define mp make_pair
#define si(x) int(x.size())
const int mod=998244353,MAX=300005,INF=1<<30;
// フローのみ

// from: https://gist.github.com/yosupo06/ddd51afb727600fd95d9d8ad6c3c80c9
// (based on AtCoder STL)

#ifndef ATCODER_INTERNAL_QUEUE_HPP
#define ATCODER_INTERNAL_QUEUE_HPP 1
#include <vector>
namespace atcoder {
    namespace internal {
        template <class T> struct simple_queue {
            std::vector<T> payload;
            int pos = 0;
            void reserve(int n) { payload.reserve(n); }
            int size() const { return int(payload.size()) - pos; }
            bool empty() const { return pos == int(payload.size()); }
            void push(const T& t) { payload.push_back(t); }
            T& front() { return payload[pos]; }
            void clear() {
                payload.clear();
                pos = 0;
            }
            void pop() { pos++; }
        };
    }  // namespace internal
}  // namespace atcoder
#endif  // ATCODER_INTERNAL_QUEUE_HPP

#ifndef ATCODER_MAXFLOW_HPP
#define ATCODER_MAXFLOW_HPP 1
#include <algorithm>
#include <cassert>
#include <limits>
#include <queue>
#include <vector>
namespace atcoder {
    template <class Cap> struct mf_graph {
    public:
        mf_graph() : _n(0) {}
        mf_graph(int n) : _n(n), g(n) {}
        int add_edge(int from, int to, Cap cap) {
            assert(0 <= from && from < _n);
            assert(0 <= to && to < _n);
            assert(0 <= cap);
            int m = int(pos.size());
            pos.push_back({from, int(g[from].size())});
            g[from].push_back(_edge{to, int(g[to].size()), cap});
            g[to].push_back(_edge{from, int(g[from].size()) - 1, 0});
            return m;
        }
        struct edge {
            int from, to;
            Cap cap, flow;
        };
        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};
        }
        std::vector<edge> edges() {
            int m = int(pos.size());
            std::vector<edge> result;
            for (int i = 0; i < m; i++) {
                result.push_back(get_edge(i));
            }
            return result;
        }
        void change_edge(int i, Cap new_cap, Cap new_flow) {
            int m = int(pos.size());
            assert(0 <= i && i < m);
            assert(0 <= new_flow && new_flow <= new_cap);
            auto& _e = g[pos[i].first][pos[i].second];
            auto& _re = g[_e.to][_e.rev];
            _e.cap = new_cap - new_flow;
            _re.cap = new_flow;
        }
        Cap flow(int s, int t) {
            return flow(s, t, std::numeric_limits<Cap>::max());
        }
        Cap flow(int s, int t, Cap flow_limit) {
            assert(0 <= s && s < _n);
            assert(0 <= t && t < _n);
            std::vector<int> level(_n), iter(_n);
            internal::simple_queue<int> que;
            auto bfs = [&]() {
                std::fill(level.begin(), level.end(), -1);
                level[s] = 0;
                que.clear();
                que.push(s);
                while (!que.empty()) {
                    int v = que.front();
                    que.pop();
                    for (auto e : g[v]) {
                        if (e.cap == 0 || level[e.to] >= 0) continue;
                        level[e.to] = level[v] + 1;
                        if (e.to == t) return;
                        que.push(e.to);
                    }
                }
            };
            auto dfs = [&](auto self, int v, Cap up) {
                if (v == s) return up;
                Cap res = 0;
                int level_v = level[v];
                for (int& i = iter[v]; i < int(g[v].size()); i++) {
                    _edge& e = g[v][i];
                    if (level_v <= level[e.to] || g[e.to][e.rev].cap == 0) continue;
                    Cap d =
                    self(self, e.to, std::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;
            };
            Cap flow = 0;
            while (flow < flow_limit) {
                bfs();
                if (level[t] == -1) break;
                std::fill(iter.begin(), iter.end(), 0);
                while (flow < flow_limit) {
                    Cap f = dfs(dfs, t, flow_limit - flow);
                    if (!f) break;
                    flow += f;
                }
            }
            return flow;
        }
        std::vector<bool> min_cut(int s) {
            std::vector<bool> visited(_n);
            internal::simple_queue<int> que;
            que.push(s);
            while (!que.empty()) {
                int p = que.front();
                que.pop();
                visited[p] = true;
                for (auto e : g[p]) {
                    if (e.cap && !visited[e.to]) {
                        visited[e.to] = true;
                        que.push(e.to);
                    }
                }
            }
            return visited;
        }
    private:
        int _n;
        struct _edge {
            int to, rev;
            Cap cap;
        };
        std::vector<std::pair<int, int>> pos;
        std::vector<std::vector<_edge>> g;
    };
}  // namespace atcoder
#endif  // ATCODER_MAXFLOW_HPP
#ifndef ATCODER_MINCOSTFLOW_HPP
#define ATCODER_MINCOSTFLOW_HPP 1
#include <algorithm>
#include <cassert>
#include <limits>
#include <queue>
#include <vector>
namespace atcoder {
    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);
            // variants (C = maxcost):
            // -(n-1)C <= dual[s] <= dual[i] <= dual[t] = 0
            // reduced cost (= e.cost + dual[e.from] - dual[e.to]) >= 0 for all edge
            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;
                    // dist[v] = shortest(s, v) + dual[s] - dual[v]
                    // dist[v] >= 0 (all reduced cost are positive)
                    // dist[v] <= (n-1)C
                    for (int i = 0; i < int(g[v].size()); i++) {
                        auto e = g[v][i];
                        if (vis[e.to] || !e.cap) continue;
                        // |-dual[e.to] + dual[v]| <= (n-1)C
                        // cost <= C - -(n-1)C + 0 = nC
                        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] = dual[v] - dist[t] + dist[v]
                    //         = dual[v] - (shortest(s, t) + dual[s] - dual[t]) + (shortest(s, v) + dual[s] - dual[v])
                    //         = - shortest(s, t) + dual[t] + shortest(s, v)
                    //         = shortest(s, v) - shortest(s, t) >= 0 - (n-1)C
                    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 = d;
            }
            return result;
        }
    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;
    };
}  // namespace atcoder
#endif  // ATCODER_MINCOSTFLOW_HPP

int main(){
    
    std::ifstream in("text.txt");
    std::cin.rdbuf(in.rdbuf());
    cin.tie(0);
    ios::sync_with_stdio(false);
    
    int N,M;cin>>N>>M;
    int s=4*N,t=4*N+1;
    atcoder::mcf_graph<ll,ll> G(4*N+2);
    for(int i=0;i<N;i++){
        if(i){
            G.add_edge(i,2*N+i-1,1,0);
            G.add_edge(2*N+i,2*N+i-1,N,0);
        }
        G.add_edge(2*N+i,N+i,1,INF);
        
        if(i+1<N){
            G.add_edge(i,3*N+i+1,1,0);
            G.add_edge(3*N+i,3*N+i+1,N,0);
        }
        G.add_edge(3*N+i,N+i,1,INF);
        
        G.add_edge(s,i,1,0);
        G.add_edge(N+i,t,1,0);
    }
    
    for(int i=0;i<M;i++){
        int a,b;cin>>a>>b;a--;b--;
        G.add_edge(a,N+b,1,0);
        G.add_edge(b,N+a,1,0);
    }
    
    ll ans=-N+2*(N-G.flow(s,t,N).se/INF);
    
    cout<<ans<<endl;
}

yukicoder

結果

テストケース

ソースコード