#540369 (C++17) No.340 雪の足跡

• 問題: No.340 雪の足跡
• ユーザー: T1610
• 提出日時: 2020-08-25 23:41:21
• 言語: C++17 (gcc 13.3.0 + boost 1.87.0)
• 結果: AC
• 実行時間: 875 ms / 1,000 ms
• コード長: 11,381 bytes
• コンパイル時間: 2,620 ms
• コンパイル使用メモリ: 214,948 KB
• 最終ジャッジ日時: 2025-01-13 14:54:48
• ジャッジサーバーID （参考情報）: judge5 / judge4

ファイルパターン	結果
sample	AC * 5
other	AC * 32

ソースコード

#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) REP(i,0,n)
#define REP(i,s,e) for(int i=(s); i<(int)(e); i++)
#define repr(i, n) REPR(i, n, 0)
#define REPR(i, s, e) for(int i=(int)(s-1); i>=(int)(e); i--)
#define all(r) r.begin(),r.end()
#define rall(r) r.rbegin(),r.rend()

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;

const ll INF = 1e18;
const ll MOD = 1e9 + 7;

template<typename T> T chmax(T& a, const T& b){return a = (a > b ? a : b);}
template<typename T> T chmin(T& a, const T& b){return a = (a < b ? a : b);}

#define DEBUG_MODE
#ifdef DEBUG_MODE
#define dump(x) cout << #x << " : " << x << " "
#define dumpL(x) cout << #x << " : " << x << '\n'
#define LINE cout << "line : " << __LINE__ << " "
#define LINEL cout << "line : " << __LINE__ << '\n'
#define dumpV(v) cout << #v << " : ["; for(auto& t : v) cout << t << ", "; cout<<"]" << " "
#define dumpVL(v) cout << #v << " : ["; for(auto& t : v) cout << t << ", "; cout<<"]" << endl
#define STOP assert(false)
#else
#define dump(x) 
#define dumpL(x) 
#define LINE 
#define LINEL 
#define dumpV(v) 
#define dumpVL(v) 
#define STOP assert(false)
#endif
#define mp make_pair
 
namespace std {
template<class S, class T>
ostream &operator <<(ostream& out, const pair<S, T>& a) {
    out << '(' << a.fi << ", " << a.se << ')';
    return out;
}
}

//有向、無向グラフ共通クラス(隣接リスト)
struct Graph {
    int n;
    using WEIGHT_TYPE = long long;
    const WEIGHT_TYPE INF = 1e18;
    struct Edge {
        int to;
        WEIGHT_TYPE weight;
    };
    struct Edge2 {
        int from;
        int to;
        WEIGHT_TYPE weight;
    };
    vector<vector<Edge>> es;
    Graph(int n) : n(n), es(n) {}

    // dijkstra O(E log V)
    vector<WEIGHT_TYPE> dijkstra(int s) {
        vector<WEIGHT_TYPE> d(n, INF);
        d[s] = 0;
        using P = pair<WEIGHT_TYPE, int>;
        priority_queue<P, vector<P>, greater<P>> q;
        q.push({0LL, s});
        while(!q.empty()) {
            auto p = q.top();
            q.pop();
            int cur = p.second;
            auto cost = p.first;
            if(d[cur] < p.first) continue;
            for(auto &e : es[cur]) {
                int to = e.to;
                auto dist = e.weight + cost;
                if(dist < d[to]) {
                    d[to] = dist;
                    q.push({dist, to});
                }
            }
        }
        return d;
    }
    // dijkstra O(V^2)
    vector<WEIGHT_TYPE> dijkstra2(int s) {
        vector<WEIGHT_TYPE> d(n, INF);
        d[s] = 0;
        vector<int> used(n);
        auto mat = getEdgeMat();
        while(1) {
            int cur = -1;
            rep(i, n) {
                if(used[i]) continue;
                if(cur == -1 || d[i] < d[cur]) cur = i;
            }
            if(cur == -1) break;
            used[cur] = 1;
            rep(i, n) { chmin(d[i], d[cur] + mat[cur][i]); }
        }
        return d;
    }
    // warshall_floyd O(n^3)
    vector<vector<WEIGHT_TYPE>> warshall_floyd() {
        // vector<vector<WEIGHT_TYPE>> d(n, vector<WEIGHT_TYPE>(n, INF));
        // rep(i, n) d[i][i] = 0LL;
        // rep(i, n) for (auto && e : es[i]) {
        //     int j = e.to;
        //     chmin(d[i][j], e.weight);
        // }
        auto d = getEdgeMat();
        rep(k, n) rep(i, n) rep(j, n) { chmin(d[i][j], d[i][k] + d[k][j]); }
        return d;
    }
    // 頂点sから到達できるか
    vector<bool> getVisitable(int s) {
        vector<bool> ret(n);
        queue<int> q;
        q.push(s);
        ret[s] = true;
        while(!q.empty()) {
            auto cur = q.front();
            q.pop();
            for(auto &&e : es[cur]) {
                if(!ret[e.to]) {
                    ret[e.to] = true;
                    q.push(e.to);
                }
            }
        }
        return ret;
    }
    // 2部グラフ判定
    bool isBipartile() {
        vector<int> memo(n, -1);
        rep(i, n) {
            if(memo[i] != -1) continue;
            queue<int> q;
            q.push(i);
            memo[i] = 0;
            while(!q.empty()) {
                auto v = q.front();
                q.pop();
                for(auto &&e : es[v]) {
                    auto u = e.to;
                    if(memo[u] == -1) {
                        memo[u] = !memo[v];
                        q.push(u);
                    } else if(memo[u] == memo[v]) {
                        return false;
                    }
                }
            }
        }
        return true;
    }
    vector<vector<WEIGHT_TYPE>> getEdgeMat() {
        vector<vector<WEIGHT_TYPE>> mat(n, vector<WEIGHT_TYPE>(n, INF));
        rep(i, n) mat[i][i] = 0;
        rep(i, n) {
            for(auto &&e : es[i]) chmin(mat[i][e.to], e.weight);
        }
        return mat;
    }
};

// 無向グラフ
struct GraphUD : public Graph {
    GraphUD(int n) : Graph(n) {}
    void add_edge(int from, int to, WEIGHT_TYPE weight) {
        es[from].push_back({to, weight});
        es[to].push_back({from, weight});
    }
    vector<Edge2> getEdge2() {
        vector<Edge2> ret;
        rep(i, n) for(auto &&e : es[i]) {
            if(i < e.to) ret.push_back({i, e.to, e.weight});
        }
        return ret;
    }
    // 橋の検出
    // http://nupioca.hatenadiary.jp/entry/2013/11/03/200006
    // Calculate bridges in a undirected graph.
    // Assume graph is connected and has no parallel edges or self-loops.
    vector<Edge2> getBridges() {
        int V = n;
        // res: bridges
        vector<Edge2> res;
        // assume at least the first vertex exists
        vector<int> low(V, -1); // lowest reacheable index
        vector<int> pre(V, -1); // pre-order index
        int count = 0;          // pre-order index counter

        // v: current node
        // from: parent node
        function<int(int, int)> dfs = [&](int v, int from) {
            pre[v] = count++;
            low[v] = pre[v];
            for(auto &&e : es[v]) {
                int to = e.to;
                if(pre[to] == -1) {
                    // destination has not been visited
                    // visit destination and update low[v]
                    low[v] = min(low[v], dfs(to, v));
                    if(low[to] == pre[to]) {
                        // edge is not contained in a closed path -> bridge
                        res.push_back({v, to, e.weight});
                    }
                } else {
                    if(from == to) {
                        // ignore a path to parent
                        continue;
                    }
                    low[v] = min(low[v], low[to]);
                }
            }
            return low[v];
        };

        dfs(0, -1); // start dfs from vertex 0

        return res;
    }
};

// 有向グラフ
struct GraphD : public Graph {
    GraphD(int n) : Graph(n) {}
    void add_edge(int from, int to, WEIGHT_TYPE weight) {
        es[from].push_back({to, weight});
    }
    vector<Edge2> getEdge2() {
        vector<Edge2> ret;
        rep(i, n) for(auto &&e : es[i]) { ret.push_back({i, e.to, e.weight}); }
        return ret;
    }
    GraphD getReverseGraph() {
        GraphD g(n);
        rep(i, n) for(auto &&e : es[i]) { g.add_edge(e.to, i, e.weight); }
        return g;
    }
    vector<vector<int>> scc() {
        vector<vector<int>> res;
        vector<int> cmp(n);
        vector<int> vs;
        vector<vector<int>> r_es(n);
        rep(i, n) for(auto &&e : es[i]) {
            int j = e.to;
            r_es[j].push_back(i);
        }

        vector<bool> used(n);
        function<void(int)> dfs = [&](int v) {
            used[v] = true;
            for(auto &&e : es[v]) {
                int to = e.to;
                if(!used[to]) dfs(to);
            }
            vs.push_back(v);
        };
        function<void(int, int)> rdfs = [&](int v, int k) {
            used[v] = true;
            cmp[v] = k;
            for(auto &&to : r_es[v]) {
                if(!used[to]) rdfs(to, k);
            }
        };

        fill(all(used), 0);
        vs.clear();
        for(int v = 0; v < n; v++) {
            if(!used[v]) dfs(v);
        }
        fill(all(used), 0);
        int k = 0;
        for(int i = vs.size() - 1; i >= 0; i--) {
            if(!used[vs[i]]) rdfs(vs[i], k++);
        }
        res.clear();
        res.resize(k);
        for(int i = 0; i < n; i++) {
            res[cmp[i]].push_back(i);
        }
        return res;
    }
    // bellmanFord 負閉路があるなら, dist[s] = INF | O(VE)
    vector<WEIGHT_TYPE> bellmanFord(int s) {
        vector<WEIGHT_TYPE> dist(n, INF);
        dist[s] = 0;
        auto es = getEdge2();
        rep(i, n) {
            for(auto &&e : es) {
                if(dist[e.to] > dist[e.from] + e.weight) {
                    dist[e.to] = dist[e.from] + e.weight;
                    if(i == n - 1) {
                        dist[s] = INF;
                        return dist;
                    }
                }
            }
        }
        return dist;
    }
    // bellmanFord s->tの経路上に負閉路があるなら, dist[s] = INF | O(VE)
    vector<WEIGHT_TYPE> bellmanFord2(int s, int t) {
        vector<WEIGHT_TYPE> dist(n, INF);
        auto f1 = getVisitable(s);
        auto f2 = getReverseGraph().getVisitable(t);
        dist[s] = 0;
        auto es = getEdge2();
        rep(i, n) {
            for(auto &&e : es) {
                if(!(f1[e.from] && f2[e.to])) continue;
                if(dist[e.to] > dist[e.from] + e.weight) {
                    dist[e.to] = dist[e.from] + e.weight;
                    if(i == n - 1) {
                        dist[s] = INF;
                        return dist;
                    }
                }
            }
        }
        return dist;
    }
};

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    int w, h, n;
    cin >> w >> h >> n;
    vector<vi> r(w, vi(h));
    vector<vi> c(h, vi(w));

    rep(_, n) {
        int m;
        cin >> m;
        ++m;
        vi b(m);
        rep(i, m) cin >> b[i];
        rep(i, m-1) {
            int sx = b[i] % w, sy = b[i] / w;
            int tx = b[i+1] % w, ty = b[i+1] / w;
            // cout << " " << b[i] << " " << sy << " " << sx << '\n';
            // cout << " " << b[i+1] << " " << ty << " " << tx << '\n';
            if(sx == tx) {
                if(sy > ty) swap(sy, ty);
                r[sx][sy] += 1;
                r[sx][ty] -= 1;
                // cout << "r " << sx << " " << sy << " " << ty << '\n'; 
            }
            else {
                if(sx > tx) swap(sx, tx);
                c[sy][sx] += 1;
                c[sy][tx] -= 1;
                // cout << "c " << sy << " " << sx << " " << tx << '\n'; 
            }
        }
    }

    rep(i, r.size()) rep(j, r[i].size()-1) r[i][j+1] += r[i][j];
    rep(i, c.size()) rep(j, c[i].size()-1) c[i][j+1] += c[i][j];


    GraphUD g(h * w);
    rep(x, w) rep(y, h-1) if(r[x][y]) {
        int cur = y * w + x;
        int nxt = cur + w;
        g.add_edge(cur, nxt, +1);
    }
    rep(y, h) rep(x, w-1) if(c[y][x]) {
        int cur = y * w + x;
        int nxt = cur + 1;
        g.add_edge(cur, nxt, +1);
    }

    auto d = g.dijkstra(0)[h * w - 1];
    if(d == g.INF) cout << "Odekakedekinai.." << '\n';
    else cout << d << '\n';
    return 0;
}