結果

問題 No.1190 Points
ユーザー sten_san
提出日時 2021-02-14 00:49:29
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 199 ms / 2,000 ms
コード長 3,924 bytes
コンパイル時間 2,195 ms
コンパイル使用メモリ 212,928 KB
最終ジャッジ日時 2025-01-18 20:15:44
ジャッジサーバーID
（参考情報） 		judge5 / judge3
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ファイルパターン 結果
sample AC * 3
other AC * 25
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;

struct iofast_t {
    iofast_t() {
        ios::sync_with_stdio(false);
        cin.tie(nullptr); cout.tie(nullptr);
    }
} iofast;

struct uns_t {} uns;
template <typename Element, typename Head, typename ...Args>
auto vec(Element init, Head arg, Args ...args) {
    if constexpr (sizeof...(Args) == 0) return std::vector(arg, init);
    else return std::vector(arg, vec(init, args...));
}
template <typename Element, typename Head, typename ...Args>
auto vec(uns_t, Head arg, Args ...args) {
    return vec(Element(), arg, args...);
}

template <typename T>
using pqueue = priority_queue<T, vector<T>, greater<T>>;

int main() {
    constexpr int inf = INT_MAX / 4;

    int n, m, p; cin >> n >> m >> p;
    int start, goal; cin >> start >> goal; --start; --goal;

    auto g = vec<int>(uns, n, 0);
    for (int i = 0; i < m; ++i) {
        int u, v; cin >> u >> v; --u; --v;
        g[u].push_back(v);
        g[v].push_back(u);
    }

    auto bfs = [&](int s) {
        auto dist = vec<int>(-1, n);
        queue<int> que;

        dist[s] = 0;
        que.push(s);
        while (!que.empty()) {
            int c = que.front(); que.pop();
            for (auto v : g[c]) {
                if (0 <= dist[v]) continue;
                dist[v] = dist[c] + 1;
                que.push(v);
            }
        }

        return dist;
    };

    auto dist1_s = bfs(start);
    auto dist1_g = bfs(goal);

    auto start_s = vec<tuple<int, int>>(uns, 0);
    auto start_g = vec<tuple<int, int>>(uns, 0);

    for (int u = 0; u < n; ++u) {
        for (auto v : g[u]) {
            if (dist1_s[u] == dist1_s[v]) {
                start_s.emplace_back(dist1_s[v] + 1, u);
                start_s.emplace_back(dist1_s[v] + 1, v);
            }
            if (dist1_g[u] == dist1_g[v]) {
                start_g.emplace_back(dist1_g[v] + 1, u);
                start_g.emplace_back(dist1_g[v] + 1, v);
            }
        }
    }

    if (size(start_s) == 0 && size(start_g) == 0) {
        auto ans = vec<int>(uns, 0);

        for (int i = 0; i < n; ++i) {
            auto d = dist1_s[i] + dist1_g[i];
            if (d <= p && d % 2 == p % 2) {
                ans.push_back(i + 1);
            }
        }

        if (size(ans) != 0) {
            cout << size(ans) << endl;
            for (auto e : ans) {
                cout << e << endl;
            }
        }
        else {
            cout << -1 << endl;
        }

        return 0;
    }

    auto dijkstra = [&](auto &&vtxs) {
        auto dist = vec<int>(inf, n);
        pqueue<tuple<int, int>> que;

        for (auto [c, v] : vtxs) {
            dist[v] = min(dist[v], c);
            que.push({ c, v });
        }

        while (!que.empty()) {
            auto [_, u] = que.top(); que.pop();
            for (auto v : g[u]) {
                if (dist[v] <= dist[u] + 1) continue;
                dist[v] = dist[u] + 1;
                que.push({ dist[v], v });
            }
        }

        return dist;
    };

    auto dist2_s = dijkstra(start_s);
    auto dist2_g = dijkstra(start_g);

    auto ans = vec<int>(uns, 0);
    for (int i = 0; i < n; ++i) {
        auto d1 = dist1_s[i];
        auto d2 = dist2_s[i];
        auto d3 = dist1_g[i];
        auto d4 = dist2_g[i];
        if (d1 < 0 || d3 < 0) continue;

        if (d1 % 2 == 1) {
            swap(d1, d2);
        }
        if (d3 % 2 == 1) {
            swap(d3, d4);
        }

        if (p % 2 == 0) {
            if (d1 + d3 <= p || d2 + d4 <= p) {
                ans.push_back(i + 1);
            }
        }
        else {
            if (d1 + d4 <= p || d2 + d3 <= p) {
                ans.push_back(i + 1);
            }
        }
    }

    if (size(ans) != 0) {
        cout << size(ans) << endl;
        for (auto e : ans) {
            cout << e << endl;
        }
    }
    else {
        cout << -1 << endl;
    }
}
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