Submission #1183655

#	Time	Username	Problem	Language	Result	Execution time	Memory
1183655		meicris	Toll (BOI17_toll)	C++17	8 / 100	3111 ms	537468 KiB

toll

#include <bits/stdc++.h>
using namespace std;

const int INF = 1e9;
int K, N, M, O;

vector<vector<pair<int, int>>> graph;
unordered_map<int, vector<int>> dist_cache;

vector<int>& dijkstra(int s) {
    vector<int>& dist = dist_cache[s];
    dist.assign(N, INF);
    dist[s] = 0;
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<>> pq;
    pq.push({0, s});

    while (!pq.empty()) {
        auto [d, u] = pq.top(); pq.pop();
        if (d > dist[u]) continue;

        for (auto& [v, cost] : graph[u]) {
            if (dist[v] > d + cost) {
                dist[v] = d + cost;
                pq.push({dist[v], v});
            }
        }
    }

    return dist;
}

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

    cin >> K >> N >> M >> O;
    graph.resize(N);

    for (int i = 0; i < M; ++i) {
        int a, b, t;
        cin >> a >> b >> t;
        if (b / K == (a / K) + 1)
            graph[a].emplace_back(b, t);
    }

    while (O--) {
        int a, b;
        cin >> a >> b;
        if (!dist_cache.count(a)) dist_cache[a].resize(N);
        vector<int>& d = dist_cache[a][0] ? dist_cache[a] : dijkstra(a);
        int res = d[b];
        cout << (res == INF ? -1 : res) << '\n';
    }
}

• Subtask 1: 0 / 7
• Subtask 2: 0 / 10
• Subtask 3: 8 / 8
• Subtask 4: 0 / 31
• Subtask 5: 0 / 44