oj.uz

Submission #517013

# Submission time Handle Problem Language Result Execution time Memory
517013 2022-01-22T11:16:22 Z nighty Commuter Pass (JOI18_commuter_pass) C++14
55 / 100
 2000 ms 20884 KB 
#include <bits/stdc++.h>

using namespace std;

vector<int> last;

set<pair<int, int>> choosenE;

vector<long long> dijkstra(int start, vector<vector<pair<int, int>>>& g) {
    int n = g.size();
    vector<long long> d(n, numeric_limits<long long>::max());
    last.assign(n, -1);
    d[start] = 0;
    set<pair<long long, int>> s; // {d[i], i}
    s.insert({0, start});
    while (!s.empty()) {
        int i = s.begin()->second;
        s.erase(s.begin());
        for (auto [j, w] : g[i]) {
            if (d[i] + w < d[j]) {
                s.erase({d[j], j});
                d[j] = d[i] + w;
                last[j] = i;
                s.insert({d[j], j});
            }
        }
    }
    return d;
}

vector<long long> dijkstra2(int start, vector<vector<pair<int, int>>>& g) {
    int n = g.size();
    vector<long long> d(n, numeric_limits<long long>::max());
    last.assign(n, -1);
    d[start] = 0;
    set<pair<long long, int>> s; // {d[i], i}
    s.insert({0, start});
    while (!s.empty()) {
        int i = s.begin()->second;
        s.erase(s.begin());
        for (auto [j, w] : g[i]) {
            if (choosenE.find({i, j}) != choosenE.end() || choosenE.find({j, i}) != choosenE.end()) {
                w = 0;
            }
            if (d[i] + w < d[j]) {
                s.erase({d[j], j});
                d[j] = d[i] + w;
                last[j] = i;
                s.insert({d[j], j});
            }
        }
    }
    return d;
}

vector<long long> dijkstraCnt(int start, vector<vector<pair<int, int>>>& g) {
    int n = g.size();
    vector<long long> d(n, numeric_limits<long long>::max()), cnt(n, 0);
    last.assign(n, -1);
    d[start] = 0;
    cnt[start] = 1;
    set<pair<long long, int>> s; // {d[i], i}
    s.insert({0, start});
    while (!s.empty()) {
        int i = s.begin()->second;
        s.erase(s.begin());
        for (auto [j, w] : g[i]) {
            if (d[i] + w < d[j]) {
                s.erase({d[j], j});
                d[j] = d[i] + w;
                cnt[j] = cnt[i];
                last[j] = i;
                s.insert({d[j], j});
            } else if (d[i] + w == d[j]) {
                cnt[j] += cnt[i];
            }
        }
    }
    return cnt;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, m;
    cin >> n >> m;
    int s, t;
    cin >> s >> t;
    --s, --t;
    int u, v;
    cin >> u >> v;
    --u, --v;
    vector<vector<pair<int, int>>> g(n);
    for (int _m = 0; _m < m; ++_m) {
        int a, b, w;
        cin >> a >> b >> w;
        --a, --b;
        g[a].push_back({b, w});
        g[b].push_back({a, w});
    }
    if (s == u) {
        long long minDistST = dijkstra(s, g)[t];
        auto dT = dijkstra(t, g), dV = dijkstra(v, g), dS = dijkstra(s, g);
        long long res = numeric_limits<long long>::max();
        for (int i = 0; i < n; ++i) {
            if (dS[i] + dT[i] == minDistST) {
                res = min(res, dV[i]);
            }
        }
        cout << res << '\n';
        return 0;
    }
    if (dijkstraCnt(s, g)[t] == 1) {
        dijkstra(s, g);
        while (t >= 0) {
            choosenE.insert({last[t], t});
            t = last[t];
        }
        auto d = dijkstra2(u, g);
        cout << d[v] << '\n';
        return 0;
    }

    long long minDistST = dijkstra(s, g)[t];
    auto dT = dijkstra(t, g), dV = dijkstra(v, g), dS = dijkstra(s, g), dU = dijkstra(u, g);
    long long res = dU[v];
    for (int i = 0; i < n; ++i) {
        auto di = dijkstra(i, g);
        for (int j = 0; j < n; ++j) {
            if (min(dS[i] + dT[j], dS[j] + dT[i]) + di[j] == minDistST) {
                res = min(res, min(dU[i] + dV[j], dU[j] + dV[i]));
            }
        }
    }
    cout << res << '\n';
    return 0;
}

Compilation message

commuter_pass.cpp: In function 'std::vector<long long int> dijkstra(int, std::vector<std::vector<std::pair<int, int> > >&)':
commuter_pass.cpp:19:19: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   19 |         for (auto [j, w] : g[i]) {
      |                   ^
commuter_pass.cpp: In function 'std::vector<long long int> dijkstra2(int, std::vector<std::vector<std::pair<int, int> > >&)':
commuter_pass.cpp:41:19: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   41 |         for (auto [j, w] : g[i]) {
      |                   ^
commuter_pass.cpp: In function 'std::vector<long long int> dijkstraCnt(int, std::vector<std::vector<std::pair<int, int> > >&)':
commuter_pass.cpp:67:19: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   67 |         for (auto [j, w] : g[i]) {
      |                   ^

Subtask #1
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 470 ms 14700 KB Output is correct
2 Correct 394 ms 13524 KB Output is correct
3 Correct 328 ms 13380 KB Output is correct
4 Correct 387 ms 14792 KB Output is correct
5 Correct 347 ms 13620 KB Output is correct
6 Correct 462 ms 14732 KB Output is correct
7 Correct 353 ms 13692 KB Output is correct
8 Correct 363 ms 13740 KB Output is correct
9 Correct 410 ms 13704 KB Output is correct
10 Correct 256 ms 13988 KB Output is correct
11 Correct 106 ms 8504 KB Output is correct
12 Correct 412 ms 13524 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 504 ms 13984 KB Output is correct
2 Correct 502 ms 13852 KB Output is correct
3 Correct 459 ms 13084 KB Output is correct
4 Correct 478 ms 13732 KB Output is correct
5 Correct 530 ms 14264 KB Output is correct
6 Correct 444 ms 14756 KB Output is correct
7 Correct 519 ms 15044 KB Output is correct
8 Correct 500 ms 13856 KB Output is correct
9 Correct 456 ms 14176 KB Output is correct
10 Correct 480 ms 13500 KB Output is correct
11 Correct 156 ms 9784 KB Output is correct
12 Correct 450 ms 14852 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 45 ms 972 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 25 ms 332 KB Output is correct
4 Correct 14 ms 1612 KB Output is correct
5 Correct 53 ms 1012 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 44 ms 332 KB Output is correct
8 Correct 2 ms 332 KB Output is correct
9 Correct 37 ms 332 KB Output is correct
10 Correct 60 ms 1012 KB Output is correct
11 Correct 1 ms 332 KB Output is correct
12 Correct 1 ms 332 KB Output is correct
13 Correct 21 ms 360 KB Output is correct
14 Correct 31 ms 332 KB Output is correct
15 Correct 1 ms 364 KB Output is correct

Subtask #4
0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 470 ms 14700 KB Output is correct
2 Correct 394 ms 13524 KB Output is correct
3 Correct 328 ms 13380 KB Output is correct
4 Correct 387 ms 14792 KB Output is correct
5 Correct 347 ms 13620 KB Output is correct
6 Correct 462 ms 14732 KB Output is correct
7 Correct 353 ms 13692 KB Output is correct
8 Correct 363 ms 13740 KB Output is correct
9 Correct 410 ms 13704 KB Output is correct
10 Correct 256 ms 13988 KB Output is correct
11 Correct 106 ms 8504 KB Output is correct
12 Correct 412 ms 13524 KB Output is correct
13 Correct 504 ms 13984 KB Output is correct
14 Correct 502 ms 13852 KB Output is correct
15 Correct 459 ms 13084 KB Output is correct
16 Correct 478 ms 13732 KB Output is correct
17 Correct 530 ms 14264 KB Output is correct
18 Correct 444 ms 14756 KB Output is correct
19 Correct 519 ms 15044 KB Output is correct
20 Correct 500 ms 13856 KB Output is correct
21 Correct 456 ms 14176 KB Output is correct
22 Correct 480 ms 13500 KB Output is correct
23 Correct 156 ms 9784 KB Output is correct
24 Correct 450 ms 14852 KB Output is correct
25 Correct 45 ms 972 KB Output is correct
26 Correct 1 ms 332 KB Output is correct
27 Correct 25 ms 332 KB Output is correct
28 Correct 14 ms 1612 KB Output is correct
29 Correct 53 ms 1012 KB Output is correct
30 Correct 1 ms 332 KB Output is correct
31 Correct 44 ms 332 KB Output is correct
32 Correct 2 ms 332 KB Output is correct
33 Correct 37 ms 332 KB Output is correct
34 Correct 60 ms 1012 KB Output is correct
35 Correct 1 ms 332 KB Output is correct
36 Correct 1 ms 332 KB Output is correct
37 Correct 21 ms 360 KB Output is correct
38 Correct 31 ms 332 KB Output is correct
39 Correct 1 ms 364 KB Output is correct
40 Correct 383 ms 20884 KB Output is correct
41 Correct 351 ms 17404 KB Output is correct
42 Correct 442 ms 17340 KB Output is correct
43 Execution timed out 2067 ms 12264 KB Time limit exceeded
44 Halted 0 ms 0 KB -