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Submission #721597

# Submission time Handle Problem Language Result Execution time Memory
721597 2023-04-11T05:17:08 Z dxz05 Event Hopping (BOI22_events) C++17
10 / 100
 1500 ms 350924 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
#define all(x) (x).begin(), (x).end()
#define MP make_pair
const int N = 100500;

vector<int> g[N];
int n;
int d[N];

void bfs(int x){
    fill(d, d + n, 1e9);
    d[x] = 0;
    queue<int> q;
    q.push(x);
    while (!q.empty()){
        x = q.front();
        q.pop();
        for (int y : g[x]){
            if (d[y] == 1e9){
                d[y] = d[x] + 1;
                q.push(y);
            }
        }
    }
}


void solve(){
    int q;
    cin >> n >> q;

    vector<int> l(n), r(n);
    for (int i = 0; i < n; i++){
        cin >> l[i] >> r[i];
    }

    vector<int> perm(n);
    iota(all(perm), 0);

    sort(all(perm), [&](int i, int j){
        return r[i] > r[j];
    });

    set<pair<int, int>> ls;
    for (int i : perm){
        while (!ls.empty() && ls.rbegin()->first > r[i]){
            ls.erase(*ls.rbegin());
        }

        for (auto [_l, j] : ls){
            if (l[j] <= r[i] && r[i] <= r[j]){
                g[i].push_back(j);
            }
            if (l[i] <= r[j] && r[j] <= r[i]){
                g[j].push_back(i);
            }
        }

        ls.emplace(l[i], i);
    }

    for (int i = 0; i < q; i++){
        int x, y;
        cin >> x >> y;
        --x, --y;
        bfs(x);
        if (d[y] == 1e9){
            cout << "impossible" << endl;
        } else {
            cout << d[y] << endl;
        }
    }

}

int main() {
    ios_base::sync_with_stdio(false);

#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    solve();

    return 0;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Execution timed out 1547 ms 8228 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 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 4 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 3 ms 2644 KB Output is correct
6 Correct 8 ms 3412 KB Output is correct
7 Correct 19 ms 4308 KB Output is correct
8 Correct 23 ms 5332 KB Output is correct
9 Correct 86 ms 6732 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 4 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 3 ms 2644 KB Output is correct
6 Correct 8 ms 3412 KB Output is correct
7 Correct 19 ms 4308 KB Output is correct
8 Correct 23 ms 5332 KB Output is correct
9 Correct 86 ms 6732 KB Output is correct
10 Correct 1 ms 2644 KB Output is correct
11 Correct 1 ms 2644 KB Output is correct
12 Correct 3 ms 2644 KB Output is correct
13 Correct 2 ms 2644 KB Output is correct
14 Correct 3 ms 2644 KB Output is correct
15 Correct 8 ms 3412 KB Output is correct
16 Correct 19 ms 4236 KB Output is correct
17 Correct 21 ms 5332 KB Output is correct
18 Correct 87 ms 6740 KB Output is correct
19 Execution timed out 1589 ms 32464 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 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct
3 Correct 4 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 3 ms 2644 KB Output is correct
6 Correct 8 ms 3412 KB Output is correct
7 Correct 19 ms 4308 KB Output is correct
8 Correct 23 ms 5332 KB Output is correct
9 Correct 86 ms 6732 KB Output is correct
10 Correct 2 ms 2644 KB Output is correct
11 Correct 2 ms 2644 KB Output is correct
12 Correct 4 ms 2644 KB Output is correct
13 Correct 3 ms 2644 KB Output is correct
14 Correct 2 ms 2644 KB Output is correct
15 Correct 8 ms 3412 KB Output is correct
16 Correct 19 ms 4308 KB Output is correct
17 Correct 21 ms 5332 KB Output is correct
18 Correct 86 ms 6800 KB Output is correct
19 Correct 302 ms 9412 KB Output is correct
20 Correct 195 ms 9976 KB Output is correct
21 Execution timed out 1593 ms 350924 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1536 ms 8480 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Execution timed out 1547 ms 8228 KB Time limit exceeded
3 Halted 0 ms 0 KB -