oj.uz

Submission #857440

# Submission time Handle Problem Language Result Execution time Memory
857440 2023-10-06T08:01:36 Z asdasdqwer Commuter Pass (JOI18_commuter_pass) C++14
100 / 100
 299 ms 32136 KB 
// #define FMT_HEADER_ONLY
// #include <fmt/ranges.h>
#include <bits/stdc++.h>
using namespace std;

#define int int64_t
#define pii pair<int, int>

vector<int> dijkstra(int source, vector<vector<pii>> &g) {
    int n = g.size();
    vector<int> dis(n, 1e16);
    dis[source] = 0;

    priority_queue<pii> pq;
    for (int i=0;i<n;i++) {
        pq.push({-dis[i], i});
    }

    vector<bool> vis(n, false);

    while (!pq.empty()) {
        pii t = pq.top();pq.pop();
        int node = t.second;
        if (vis[node]) continue;
        vis[node] = true;

        for (pii &x:g[node]) {
            if (dis[node] + x.second < dis[x.first]) {
                dis[x.first] = dis[node] + x.second;
                pq.push({-dis[x.first], x.first});
            }
        }
    }

    return dis;
}

void dfs(int node, vector<int> &vis, vector<int> &topo, vector<vector<int>> &g) {
    vis[node] = 1;
    for (int x:g[node]) {
        if (vis[x] == 0) {
            dfs(x, vis, topo, g);
        }
    }

    vis[node] = 2;
    topo.push_back(node);
}

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

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

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

    vector<vector<pii>> g(n);

    for (int i=0;i<m;i++) {
        int a, b, c;cin>>a>>b>>c;
        a--;b--;
        g[a].push_back({b, c});
        g[b].push_back({a, c});
    }

    vector<int> disFromS = dijkstra(s, g);

    vector<vector<int>> dag(n);
    queue<int> q;
    q.push(t);
    vector<bool> proc(n, false);
    proc[t] = true;

    while (!q.empty()) {
        int tp = q.front();q.pop();
        for (pii &x:g[tp]) {
            if (disFromS[tp] == disFromS[x.first] + x.second) {
                dag[x.first].push_back(tp);
                
                if (!proc[x.first]) {
                    proc[x.first] = true;
                    q.push(x.first);
                }
            }
        }
    }

    vector<int> vis(n, 0), topo;
    
    for (int i=0;i<n;i++) {
        if (vis[i] == 0 && dag[i].size()) {
            dfs(i, vis, topo, dag);
        }
    }

    reverse(topo.begin(), topo.end());

    vector<int> disToU = dijkstra(u, g), disToV = dijkstra(v, g);
    int mn = disToV[u];

    vector<int> minGet(n, 1e16);

    for (int i=0;i<topo.size();i++) {
        int elem = topo[i];

        if (i == 0) {
            minGet[elem] = disToU[elem];
            mn = min(mn, minGet[elem] + disToV[elem]);
        }

        mn = min(mn, minGet[elem] + disToV[elem]);

        for (int x:dag[elem]) {
            minGet[x] = min(minGet[x], min(minGet[elem], disToU[x]));
            mn = min(mn, minGet[x] + disToV[x]);
        }
    }

    vector<vector<int>> rev(n);
    for (int i=0;i<n;i++) {
        for (int x:dag[i]) {
            rev[x].push_back(i);
        }
    }

    vis = vector<int>(n, 0);
    vector<int> newTopo;
    for (int i=0;i<n;i++) {
        if (vis[i] == 0 && rev[i].size()) {
            dfs(i, vis, newTopo, rev);
        }
    }

    minGet = vector<int>(n, 1e16);
    // cerr << (newTopo[0] == t) << "\n";
    // fmt::print("{}\n", newTopo);

    reverse(newTopo.begin(), newTopo.end());

    for (int i=0;i<(int)newTopo.size();i++) {
        int elem = newTopo[i];

        if (i == 0) {
            minGet[elem] = disToU[elem];
        }

        mn = min(mn, minGet[elem] + disToV[elem]);

        for (int x:rev[elem]) {
            minGet[x] = min(minGet[x], min(minGet[elem], disToU[x]));
            mn = min(mn, minGet[x] + disToV[x]);
        }
    }

    cout << mn << "\n";
}

Compilation message

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:105:19: warning: comparison of integer expressions of different signedness: 'int64_t' {aka 'long int'} and 'std::vector<long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  105 |     for (int i=0;i<topo.size();i++) {
      |                  ~^~~~~~~~~~~~

Subtask #1
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 205 ms 25352 KB Output is correct
2 Correct 223 ms 25828 KB Output is correct
3 Correct 254 ms 30656 KB Output is correct
4 Correct 225 ms 26620 KB Output is correct
5 Correct 230 ms 27748 KB Output is correct
6 Correct 239 ms 25720 KB Output is correct
7 Correct 241 ms 27524 KB Output is correct
8 Correct 238 ms 27012 KB Output is correct
9 Correct 223 ms 26876 KB Output is correct
10 Correct 211 ms 26044 KB Output is correct
11 Correct 123 ms 23488 KB Output is correct
12 Correct 206 ms 26012 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 227 ms 27284 KB Output is correct
2 Correct 246 ms 27252 KB Output is correct
3 Correct 220 ms 27936 KB Output is correct
4 Correct 229 ms 28080 KB Output is correct
5 Correct 256 ms 27428 KB Output is correct
6 Correct 224 ms 30396 KB Output is correct
7 Correct 276 ms 31908 KB Output is correct
8 Correct 279 ms 27616 KB Output is correct
9 Correct 291 ms 28244 KB Output is correct
10 Correct 255 ms 27180 KB Output is correct
11 Correct 275 ms 26012 KB Output is correct
12 Correct 299 ms 30172 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 1884 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 10 ms 3244 KB Output is correct
5 Correct 8 ms 1628 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 2 ms 604 KB Output is correct
9 Correct 1 ms 344 KB Output is correct
10 Correct 8 ms 1628 KB Output is correct
11 Correct 1 ms 344 KB Output is correct
12 Correct 1 ms 344 KB Output is correct
13 Correct 1 ms 404 KB Output is correct
14 Correct 1 ms 348 KB Output is correct
15 Correct 1 ms 348 KB Output is correct

Subtask #4
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 205 ms 25352 KB Output is correct
2 Correct 223 ms 25828 KB Output is correct
3 Correct 254 ms 30656 KB Output is correct
4 Correct 225 ms 26620 KB Output is correct
5 Correct 230 ms 27748 KB Output is correct
6 Correct 239 ms 25720 KB Output is correct
7 Correct 241 ms 27524 KB Output is correct
8 Correct 238 ms 27012 KB Output is correct
9 Correct 223 ms 26876 KB Output is correct
10 Correct 211 ms 26044 KB Output is correct
11 Correct 123 ms 23488 KB Output is correct
12 Correct 206 ms 26012 KB Output is correct
13 Correct 227 ms 27284 KB Output is correct
14 Correct 246 ms 27252 KB Output is correct
15 Correct 220 ms 27936 KB Output is correct
16 Correct 229 ms 28080 KB Output is correct
17 Correct 256 ms 27428 KB Output is correct
18 Correct 224 ms 30396 KB Output is correct
19 Correct 276 ms 31908 KB Output is correct
20 Correct 279 ms 27616 KB Output is correct
21 Correct 291 ms 28244 KB Output is correct
22 Correct 255 ms 27180 KB Output is correct
23 Correct 275 ms 26012 KB Output is correct
24 Correct 299 ms 30172 KB Output is correct
25 Correct 6 ms 1884 KB Output is correct
26 Correct 1 ms 348 KB Output is correct
27 Correct 1 ms 348 KB Output is correct
28 Correct 10 ms 3244 KB Output is correct
29 Correct 8 ms 1628 KB Output is correct
30 Correct 1 ms 348 KB Output is correct
31 Correct 1 ms 604 KB Output is correct
32 Correct 2 ms 604 KB Output is correct
33 Correct 1 ms 344 KB Output is correct
34 Correct 8 ms 1628 KB Output is correct
35 Correct 1 ms 344 KB Output is correct
36 Correct 1 ms 344 KB Output is correct
37 Correct 1 ms 404 KB Output is correct
38 Correct 1 ms 348 KB Output is correct
39 Correct 1 ms 348 KB Output is correct
40 Correct 220 ms 25164 KB Output is correct
41 Correct 214 ms 25120 KB Output is correct
42 Correct 244 ms 27232 KB Output is correct
43 Correct 147 ms 28832 KB Output is correct
44 Correct 149 ms 29216 KB Output is correct
45 Correct 283 ms 32136 KB Output is correct
46 Correct 252 ms 31912 KB Output is correct
47 Correct 221 ms 25684 KB Output is correct
48 Correct 161 ms 27720 KB Output is correct
49 Correct 183 ms 25792 KB Output is correct
50 Correct 242 ms 30088 KB Output is correct
51 Correct 295 ms 31880 KB Output is correct