oj.uz

Submission #746104

# Submission time Handle Problem Language Result Execution time Memory
746104 2023-05-21T12:37:19 Z vjudge1 Event Hopping (BOI22_events) C++17
10 / 100
 1500 ms 524288 KB 
#include <algorithm>
#include <climits>
#include <iostream>
#include <set>
#include <queue>
#include <vector>

#define int long long

using namespace std;

int const INF = INT_MAX / 3;

struct event {
    int s, e, id;
};

enum point_type {
    start,
    end,
};

struct point {
    point_type ty;
    int tm;
    int event_id;
};

vector<int> bfs(vector<vector<int>> const& graph, int const start) {
    queue<int> q;
    q.push(start);

    vector<int> dist(graph.size(), INF);
    dist[start] = 0;

    while (!q.empty()) {
        int const cur = q.front();
        q.pop();

        for (int const& neigh : graph[cur]) {
            if (dist[neigh] != INF) {
                continue;
            }

            dist[neigh] = dist[cur] + 1;
            q.push(neigh);
        }
    }

    return dist;
}

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

    int n, q;
    cin >> n >> q;

    vector<event> events(n);
    vector<point> points;

    for (int i = 0; i < n; i++) {
        cin >> events[i].s >> events[i].e;
        events[i].id = i;

        points.push_back({ point_type::start, events[i].s, i });
        points.push_back({ point_type::end, events[i].e, i });
    }

    sort(points.begin(), points.end(), [](auto const& a, auto const& b) {
        return a.tm < b.tm || (a.tm == b.tm && a.ty == point_type::start && b.ty == point_type::end);
        });

    vector<vector<int>> graph(n);

    {
        set<int> cur;
        vector<int> removed;
        int last_tm = -1;

        for (auto const& [ty, tm, e_id] : points) {
            if (tm > last_tm) {
                for (int const& r : removed) {
                    cur.erase(r);
                }

                removed.clear();
            }

            last_tm = tm;

            if (ty == point_type::start) {
                cur.insert(e_id);
            }
            else {
                removed.push_back(e_id);

                for (int const& c : cur) {
                    graph[e_id].push_back(c);
                }
            }
        }
    }

    while (q--) {
        int s, e;
        cin >> s >> e;
        s--; e--;

        auto const dist = bfs(graph, s);

        if (dist[e] == INF) {
            cout << "impossible\n";
        }
        else {
            cout << dist[e] << "\n";
        }
    }
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Execution timed out 1581 ms 15036 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 320 KB Output is correct
3 Correct 3 ms 460 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 2 ms 468 KB Output is correct
6 Correct 7 ms 1992 KB Output is correct
7 Correct 17 ms 3664 KB Output is correct
8 Correct 20 ms 5760 KB Output is correct
9 Correct 98 ms 8404 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 320 KB Output is correct
3 Correct 3 ms 460 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 2 ms 468 KB Output is correct
6 Correct 7 ms 1992 KB Output is correct
7 Correct 17 ms 3664 KB Output is correct
8 Correct 20 ms 5760 KB Output is correct
9 Correct 98 ms 8404 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 2 ms 468 KB Output is correct
13 Correct 1 ms 468 KB Output is correct
14 Correct 2 ms 468 KB Output is correct
15 Correct 7 ms 1992 KB Output is correct
16 Correct 18 ms 3668 KB Output is correct
17 Correct 22 ms 5692 KB Output is correct
18 Correct 100 ms 8524 KB Output is correct
19 Execution timed out 1569 ms 54444 KB Time limit exceeded
20 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 320 KB Output is correct
3 Correct 3 ms 460 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 2 ms 468 KB Output is correct
6 Correct 7 ms 1992 KB Output is correct
7 Correct 17 ms 3664 KB Output is correct
8 Correct 20 ms 5760 KB Output is correct
9 Correct 98 ms 8404 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 3 ms 468 KB Output is correct
13 Correct 2 ms 468 KB Output is correct
14 Correct 2 ms 468 KB Output is correct
15 Correct 7 ms 2072 KB Output is correct
16 Correct 19 ms 3688 KB Output is correct
17 Correct 22 ms 5648 KB Output is correct
18 Correct 106 ms 8528 KB Output is correct
19 Correct 364 ms 15488 KB Output is correct
20 Correct 334 ms 19392 KB Output is correct
21 Runtime error 1135 ms 524288 KB Execution killed with signal 9
22 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1519 ms 15036 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Execution timed out 1581 ms 15036 KB Time limit exceeded
3 Halted 0 ms 0 KB -