oj.uz

Submission #702209

# Submission time Handle Problem Language Result Execution time Memory
702209 2023-02-23T10:21:30 Z bebra Commuter Pass (JOI18_commuter_pass) C++17
100 / 100
 299 ms 28448 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

#define dbg(x) cerr << #x << ": " << x << endl;


const ll INF = 1e18;
const int MAX_N = 1e5 + 5;
vector<pair<int, int>> g[MAX_N];
vector<int> new_g[MAX_N];
ll dp[2][MAX_N];
ll dist[4][MAX_N];


void dfs_order(int v, vector<int>& order, vector<bool>& used) {
    used[v] = true;
    for (auto u : new_g[v]) {
        if (!used[u]) {
            dfs_order(u, order, used);
        }
    }
    order.push_back(v);
}


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

    int n, m;
    cin >> n >> m;

    int s1, t1;
    cin >> s1 >> t1;
    --s1, --t1;

    int s2, t2;
    cin >> s2 >> t2;
    --s2, --t2;

    vector<tuple<int, int, int>> edges(m);
    for (int i = 0; i < m; ++i) {
        int u, v;
        cin >> u >> v;
        --u, --v;
        int w;
        cin >> w;
        g[u].emplace_back(v, w);
        g[v].emplace_back(u, w);
        edges[i] = {u, v, w};
    }

    {
        array<int, 4> start_vertices = {s2, t2, s1, t1};
        for (int i = 0; i < 4; ++i) {
            int s = start_vertices[i];
            
            fill_n(dist[i], n, INF);
            vector<bool> used(n);

            priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> pq;
            pq.emplace(0, s);
            while (!pq.empty()) {
                auto [curr_dist, v] = pq.top();
                pq.pop();
                if (used[v]) continue;
                used[v] = true;
                dist[i][v] = curr_dist;
                for (const auto& [u, w] : g[v]) {
                    if (used[u] || curr_dist + w >= dist[i][u]) continue;
                    dist[i][u] = curr_dist + w;
                    pq.emplace(dist[i][u], u);
                }
            }
        }
    }

    {
        for (auto [u, v, w] : edges) {
            for (int t = 0; t <= 1; ++t) {
                if (dist[2][u] + w == dist[2][v] && dist[2][v] + dist[3][v] == dist[2][t1]) {
                    new_g[u].push_back(v);
                }
                swap(u, v);
            }
        }
    }

    vector<int> order;
    {
        vector<bool> used(n);
        dfs_order(s1, order, used);
        reverse(order.begin(), order.end());
    }

    fill_n(dp[0], n, INF);
    fill_n(dp[1], n, INF);

    ll ans = dist[0][t2];
    for (auto v : order) {
        for (int t = 0; t <= 1; ++t) {
            dp[t][v] = min(dp[t][v], dist[t][v]);
            for (auto u : new_g[v]) {
                dp[t][u] = min(dp[t][u], dp[t][v]);
            }
            ans = min(ans, dp[t][v] + dist[t ^ 1][v]);
        }
    }

    cout << ans << '\n';

    return 0;
}

Subtask #1
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 258 ms 23828 KB Output is correct
2 Correct 284 ms 22596 KB Output is correct
3 Correct 273 ms 28448 KB Output is correct
4 Correct 226 ms 24164 KB Output is correct
5 Correct 287 ms 23456 KB Output is correct
6 Correct 247 ms 23844 KB Output is correct
7 Correct 241 ms 23764 KB Output is correct
8 Correct 243 ms 23532 KB Output is correct
9 Correct 273 ms 22976 KB Output is correct
10 Correct 224 ms 22880 KB Output is correct
11 Correct 89 ms 20192 KB Output is correct
12 Correct 249 ms 22780 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 241 ms 24192 KB Output is correct
2 Correct 283 ms 24496 KB Output is correct
3 Correct 274 ms 23828 KB Output is correct
4 Correct 269 ms 24392 KB Output is correct
5 Correct 261 ms 25176 KB Output is correct
6 Correct 242 ms 27632 KB Output is correct
7 Correct 280 ms 28264 KB Output is correct
8 Correct 269 ms 24408 KB Output is correct
9 Correct 291 ms 25160 KB Output is correct
10 Correct 259 ms 23976 KB Output is correct
11 Correct 100 ms 22308 KB Output is correct
12 Correct 271 ms 28048 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 6356 KB Output is correct
2 Correct 3 ms 5076 KB Output is correct
3 Correct 3 ms 5076 KB Output is correct
4 Correct 16 ms 7640 KB Output is correct
5 Correct 10 ms 6316 KB Output is correct
6 Correct 3 ms 5164 KB Output is correct
7 Correct 5 ms 5204 KB Output is correct
8 Correct 4 ms 5204 KB Output is correct
9 Correct 4 ms 5076 KB Output is correct
10 Correct 9 ms 6336 KB Output is correct
11 Correct 3 ms 5076 KB Output is correct
12 Correct 3 ms 5076 KB Output is correct
13 Correct 4 ms 5032 KB Output is correct
14 Correct 4 ms 5100 KB Output is correct
15 Correct 3 ms 5076 KB Output is correct

Subtask #4
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 258 ms 23828 KB Output is correct
2 Correct 284 ms 22596 KB Output is correct
3 Correct 273 ms 28448 KB Output is correct
4 Correct 226 ms 24164 KB Output is correct
5 Correct 287 ms 23456 KB Output is correct
6 Correct 247 ms 23844 KB Output is correct
7 Correct 241 ms 23764 KB Output is correct
8 Correct 243 ms 23532 KB Output is correct
9 Correct 273 ms 22976 KB Output is correct
10 Correct 224 ms 22880 KB Output is correct
11 Correct 89 ms 20192 KB Output is correct
12 Correct 249 ms 22780 KB Output is correct
13 Correct 241 ms 24192 KB Output is correct
14 Correct 283 ms 24496 KB Output is correct
15 Correct 274 ms 23828 KB Output is correct
16 Correct 269 ms 24392 KB Output is correct
17 Correct 261 ms 25176 KB Output is correct
18 Correct 242 ms 27632 KB Output is correct
19 Correct 280 ms 28264 KB Output is correct
20 Correct 269 ms 24408 KB Output is correct
21 Correct 291 ms 25160 KB Output is correct
22 Correct 259 ms 23976 KB Output is correct
23 Correct 100 ms 22308 KB Output is correct
24 Correct 271 ms 28048 KB Output is correct
25 Correct 10 ms 6356 KB Output is correct
26 Correct 3 ms 5076 KB Output is correct
27 Correct 3 ms 5076 KB Output is correct
28 Correct 16 ms 7640 KB Output is correct
29 Correct 10 ms 6316 KB Output is correct
30 Correct 3 ms 5164 KB Output is correct
31 Correct 5 ms 5204 KB Output is correct
32 Correct 4 ms 5204 KB Output is correct
33 Correct 4 ms 5076 KB Output is correct
34 Correct 9 ms 6336 KB Output is correct
35 Correct 3 ms 5076 KB Output is correct
36 Correct 3 ms 5076 KB Output is correct
37 Correct 4 ms 5032 KB Output is correct
38 Correct 4 ms 5100 KB Output is correct
39 Correct 3 ms 5076 KB Output is correct
40 Correct 234 ms 24180 KB Output is correct
41 Correct 275 ms 22932 KB Output is correct
42 Correct 248 ms 22856 KB Output is correct
43 Correct 123 ms 22804 KB Output is correct
44 Correct 141 ms 22860 KB Output is correct
45 Correct 243 ms 25400 KB Output is correct
46 Correct 299 ms 25136 KB Output is correct
47 Correct 251 ms 23552 KB Output is correct
48 Correct 111 ms 20272 KB Output is correct
49 Correct 225 ms 23676 KB Output is correct
50 Correct 282 ms 24572 KB Output is correct
51 Correct 256 ms 25380 KB Output is correct