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답안 #575352

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
575352 2022-06-10T09:09:36 Z four_specks Commuter Pass (JOI18_commuter_pass) C++17
100 / 100
 410 ms 31372 KB 
#include <bits/stdc++.h>

using namespace std;

inline namespace
{
} // namespace

void solve()
{
    int n, m;
    cin >> n >> m;

    int s, t, u, v;
    cin >> s >> t >> u >> v, --s, --t, --u, --v;

    // cerr << s << ' ' << t << '\n';
    // cerr << u << ' ' << v << '\n';

    vector<vector<pair<int, long>>> adj(n);
    for (int i = 0; i < m; i++)
    {
        int a, b;
        long c;
        cin >> a >> b >> c, --a, --b;

        adj[a].emplace_back(b, c);
        adj[b].emplace_back(a, c);
    }

    vector<vector<int>> gr(n);
    {
        vector<long> dist(n, LONG_MAX);
        priority_queue<pair<long, int>> pq;
        vector<vector<int>> gr1(n);
        vector<vector<int>> todo(n);
        dist[s] = 0;
        for (pq.emplace(-dist[s], s); !pq.empty();)
        {
            auto [d, a] = pq.top();
            pq.pop();

            if (d != -dist[a])
                continue;

            for (int b : todo[a])
                gr1[a].push_back(b);

            for (auto [b, c] : adj[a])
            {
                if (dist[a] + c < dist[b])
                {
                    todo[b].clear(),
                    todo[b].push_back(a);

                    dist[b] = dist[a] + c;
                    pq.emplace(-dist[b], b);
                }
                else if (dist[a] + c == dist[b])
                    todo[b].push_back(a);
            }
        }

        queue<int> q;
        vector<bool> done(n, 0);
        for (q.push(t); !q.empty();)
        {
            int a = q.front();
            q.pop();

            if (done[a])
                continue;

            done[a] = 1;

            for (int b : gr1[a])
            {
                gr[b].push_back(a);
                q.push(b);
            }
        }
    }
    long res = LONG_MAX;
    {
        vector<long> dist_u(n, LONG_MAX), dist_v(n, LONG_MAX);
        {
            priority_queue<pair<long, int>> pq;
            dist_u[u] = 0;
            for (pq.emplace(-dist_u[u], u); !pq.empty();)
            {
                auto [d, a] = pq.top();
                pq.pop();

                if (d != -dist_u[a])
                    continue;

                for (auto [b, c] : adj[a])
                {
                    if (dist_u[a] + c < dist_u[b])
                    {
                        dist_u[b] = dist_u[a] + c;
                        pq.emplace(-dist_u[b], b);
                    }
                }
            }
        }
        {
            priority_queue<pair<long, int>> pq;
            dist_v[v] = 0;
            for (pq.emplace(-dist_v[v], v); !pq.empty();)
            {
                auto [d, a] = pq.top();
                pq.pop();

                if (d != -dist_v[a])
                    continue;

                for (auto [b, c] : adj[a])
                {
                    if (dist_v[a] + c < dist_v[b])
                    {
                        dist_v[b] = dist_v[a] + c;
                        pq.emplace(-dist_v[b], b);
                    }
                }
            }
        }

        res = dist_u[v];

        for (int k : {0, 1})
        {
            vector<int> deg(n);
            for (int i = 0; i < n; i++)
            {
                for (int j : gr[i])
                    deg[j]++;
            }

            vector<long> dp = dist_u;
            queue<int> q;
            for (q.push(s); !q.empty();)
            {
                int a = q.front();
                q.pop();

                res = min(res, dp[a] + dist_v[a]);

                // cerr << a << ' ' << dp[a] << ' ' << dist_v[a] << '\n';

                for (int b : gr[a])
                {
                    dp[b] = min(dp[b], dp[a]);
                    if (--deg[b] == 0)
                        q.push(b);
                }
            }

            // cerr << '\n';

            swap(u, v), swap(dist_u, dist_v);
        }
    }

    cout << res << '\n';
}

int main()
{
    ios_base::sync_with_stdio(false), cin.tie(NULL);

    solve();

    return 0;
}

Compilation message

commuter_pass.cpp: In function 'void solve()':
commuter_pass.cpp:131:18: warning: unused variable 'k' [-Wunused-variable]
  131 |         for (int k : {0, 1})
      |                  ^

Subtask #1
16.0 / 16.0

# 결과 실행 시간 메모리 Grader output
1 Correct 319 ms 28128 KB Output is correct
2 Correct 341 ms 28972 KB Output is correct
3 Correct 326 ms 30044 KB Output is correct
4 Correct 303 ms 28216 KB Output is correct
5 Correct 339 ms 29716 KB Output is correct
6 Correct 309 ms 28496 KB Output is correct
7 Correct 358 ms 30128 KB Output is correct
8 Correct 328 ms 30012 KB Output is correct
9 Correct 305 ms 28060 KB Output is correct
10 Correct 264 ms 27952 KB Output is correct
11 Correct 153 ms 23824 KB Output is correct
12 Correct 314 ms 28304 KB Output is correct

Subtask #2
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 325 ms 29748 KB Output is correct
2 Correct 394 ms 29108 KB Output is correct
3 Correct 315 ms 29304 KB Output is correct
4 Correct 364 ms 29140 KB Output is correct
5 Correct 344 ms 29596 KB Output is correct
6 Correct 322 ms 30148 KB Output is correct
7 Correct 340 ms 30276 KB Output is correct
8 Correct 339 ms 29236 KB Output is correct
9 Correct 320 ms 29656 KB Output is correct
10 Correct 354 ms 29060 KB Output is correct
11 Correct 214 ms 24444 KB Output is correct
12 Correct 317 ms 30408 KB Output is correct

Subtask #3
24.0 / 24.0

# 결과 실행 시간 메모리 Grader output
1 Correct 10 ms 2124 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 324 KB Output is correct
4 Correct 16 ms 3780 KB Output is correct
5 Correct 11 ms 2004 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 2 ms 468 KB Output is correct
8 Correct 2 ms 596 KB Output is correct
9 Correct 2 ms 468 KB Output is correct
10 Correct 7 ms 1992 KB Output is correct
11 Correct 1 ms 324 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 2 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 2 ms 328 KB Output is correct

Subtask #4
45.0 / 45.0

# 결과 실행 시간 메모리 Grader output
1 Correct 319 ms 28128 KB Output is correct
2 Correct 341 ms 28972 KB Output is correct
3 Correct 326 ms 30044 KB Output is correct
4 Correct 303 ms 28216 KB Output is correct
5 Correct 339 ms 29716 KB Output is correct
6 Correct 309 ms 28496 KB Output is correct
7 Correct 358 ms 30128 KB Output is correct
8 Correct 328 ms 30012 KB Output is correct
9 Correct 305 ms 28060 KB Output is correct
10 Correct 264 ms 27952 KB Output is correct
11 Correct 153 ms 23824 KB Output is correct
12 Correct 314 ms 28304 KB Output is correct
13 Correct 325 ms 29748 KB Output is correct
14 Correct 394 ms 29108 KB Output is correct
15 Correct 315 ms 29304 KB Output is correct
16 Correct 364 ms 29140 KB Output is correct
17 Correct 344 ms 29596 KB Output is correct
18 Correct 322 ms 30148 KB Output is correct
19 Correct 340 ms 30276 KB Output is correct
20 Correct 339 ms 29236 KB Output is correct
21 Correct 320 ms 29656 KB Output is correct
22 Correct 354 ms 29060 KB Output is correct
23 Correct 214 ms 24444 KB Output is correct
24 Correct 317 ms 30408 KB Output is correct
25 Correct 10 ms 2124 KB Output is correct
26 Correct 1 ms 332 KB Output is correct
27 Correct 1 ms 324 KB Output is correct
28 Correct 16 ms 3780 KB Output is correct
29 Correct 11 ms 2004 KB Output is correct
30 Correct 1 ms 468 KB Output is correct
31 Correct 2 ms 468 KB Output is correct
32 Correct 2 ms 596 KB Output is correct
33 Correct 2 ms 468 KB Output is correct
34 Correct 7 ms 1992 KB Output is correct
35 Correct 1 ms 324 KB Output is correct
36 Correct 1 ms 340 KB Output is correct
37 Correct 2 ms 340 KB Output is correct
38 Correct 1 ms 340 KB Output is correct
39 Correct 2 ms 328 KB Output is correct
40 Correct 302 ms 28572 KB Output is correct
41 Correct 297 ms 28220 KB Output is correct
42 Correct 308 ms 29076 KB Output is correct
43 Correct 211 ms 25608 KB Output is correct
44 Correct 185 ms 25676 KB Output is correct
45 Correct 347 ms 31372 KB Output is correct
46 Correct 410 ms 31276 KB Output is correct
47 Correct 347 ms 28828 KB Output is correct
48 Correct 167 ms 25688 KB Output is correct
49 Correct 286 ms 28200 KB Output is correct
50 Correct 339 ms 30756 KB Output is correct
51 Correct 408 ms 31292 KB Output is correct