Submission #1050075

#	Time	Username	Problem	Language	Result	Execution time	Memory
1050075		vjudge1	Commuter Pass (JOI18_commuter_pass)	C++17	0 / 100	158 ms	23660 KiB

commuter_pass

#include<bits/stdc++.h>
#define en "\n"
#define s second
#define f first
#define fast_io ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define vi vector<int>
#define vii vector<pair<int,int>>
#define int long long
#define rall(x) x.rbegin(), x.rend()
#define pb push_back
#define loop(a) for(int i = 0; i < a; i++)
#define loopv(i,a) for (int i = 0; i < a; i++)
#define all(x) (x).begin(), (x).end()
#define prDouble(x) printf("%.8f", x)
#define goog(tno) printf("Case #%d: ", tno)
using namespace std;

const int INF = INT_MAX;
typedef pair<int, int> pii;

vi dijkstra(int start, int n, vector<vector<pii>>& adj) {
    vi dist(n, INF);
    priority_queue<pii, vector<pii>, greater<pii>> pq;
    dist[start] = 0;
    pq.push({0, start});

    while (!pq.empty()) {
        int u = pq.top().second;
        int d = pq.top().first;
        pq.pop();

        if (d > dist[u]) continue;

        for (auto& edge : adj[u]) {
            int v = edge.first;
            int cost = edge.second;

            if (dist[u] + cost < dist[v]) {
                dist[v] = dist[u] + cost;
                pq.push({dist[v], v});
            }
        }
    }

    return dist;
}

signed main() {
    int N, M, S, T, U, V;
    cin>>N>>M>>S>>T>>U>>V;
    S--; T--; U--; V--;

    vector<vector<pii>> adj(N);
    vector<pair<pii, int>> edges;

    for (int i = 0; i < M; i++) {
        int A, B, C;
        cin >> A >> B >> C;
        A--; B--;
        adj[A].push_back({B, C});
        adj[B].push_back({A, C});
        edges.push_back({{A, B}, C});
    }
    vector<int> distS = dijkstra(S, N, adj);

    int min_cost = INF;
    vector<int> distU = dijkstra(U, N, adj);

    for (auto& edge : edges) {
        int A = edge.first.first;
        int B = edge.first.second;
        int C = edge.second;

        if (distS[A] + C + distS[B] == distS[T] || distS[B] + C + distS[A] == distS[T]) {
            min_cost = min(min_cost, distU[V]);
        } else {
            min_cost = min(min_cost, distU[A] + distU[B] + C);
        }
    }

    cout<<min_cost<<en;

    return 0;
}

• Subtask 1: 0 / 16
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45