Submission #1183654

#	Time	Username	Problem	Language	Result	Execution time	Memory
1183654		meicris	Toll (BOI17_toll)	C++17	18 / 100	3109 ms	507192 KiB

toll

#include <iostream>
#include <vector>
#include <queue>
#include <limits>
#include <unordered_map>
using namespace std;
const int INF = 1e9;
struct Edge {
    int to, cost;
};
int K, N, M, O;
vector<vector<Edge>> graph;
unordered_map<int, vector<int>> dist_cache;
vector<int> dijkstra(int start) {
    vector<int> dist(N, INF);
    dist[start] = 0;
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<>> pq;
    pq.push({0, start});
    while (!pq.empty()) {
        auto [d, u] = pq.top(); pq.pop();
        if (d > dist[u]) continue;
        for (const Edge& e : graph[u]) {
            if (dist[e.to] > dist[u] + e.cost) {
                dist[e.to] = dist[u] + e.cost;
                pq.push({dist[e.to], e.to});
            }
        }
    }
    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].push_back({b, t});
        }
    }
    vector<pair<int, int>> orders(O);
    for (int i = 0; i < O; ++i) {
        cin >> orders[i].first >> orders[i].second;
    }
    for (auto [start, end] : orders) {
        if (dist_cache.find(start) == dist_cache.end()) {
            dist_cache[start] = dijkstra(start);
        }
        int d = dist_cache[start][end];
        cout << (d == INF ? -1 : d) << '\n';
    }
    return 0;
}

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