oj.uz

Submission #745875

# Submission time Handle Problem Language Result Execution time Memory
745875 2023-05-21T09:04:37 Z vjudge1 Event Hopping (BOI22_events) C++14
10 / 100
 1500 ms 31404 KB 
#include <bits/stdc++.h>

using namespace std;
using ll = long long;


int main(){

    int n, q;
    cin >> n >> q;
    vector<pair<int, int> > inter(n);


    for (int i = 0; i < n; i++){
        cin >> inter[i].first >> inter[i].second;
    }

    if (n > 1000){
        set<pair<pair<int, int>, int> > s;
        for (int i = 0; i < n; i++){
            s.insert(make_pair(inter[i], i));
        }
        
        vector<ll> tav(n, -1); 
        for (ll i = 0; i < n; i++){
            if (tav[i] != -1) continue;
            queue<ll> q;
            q.push(i);
            tav[i] = i*10000000;
            while(!q.empty()){
                ll pos = q.front();
                q.pop();
                if (s.lower_bound(make_pair(make_pair(inter[pos].second, inter[pos].second), -1)) == s.end()) continue;
                ll nextPos = s.lower_bound(make_pair(make_pair(inter[pos].second, inter[pos].second), -1)) -> second;
                if (pos != n - 1 && inter[pos].second <= inter[nextPos].second && inter[pos].second >= inter[nextPos].second){
                    tav[nextPos] = tav[pos] + 1;
                    q.push(nextPos);
                }
            }
        }
        for (int i = 0; i < q; i++){
            int a, b;
            cin >> a >> b;
            a--, b--;
            if (tav[b] - tav[a] < 0 || tav[b] - tav[a] > 999999){
                cout << "impossible" << endl;
            }
            else cout << tav[b] - tav[a] << endl;
        }
    }


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

    for (int i = 0; i < n; i++){
        for (int j = 0; j < n; j++){
            if (i == j) continue;
            if (inter[i].second <= inter[j].second && inter[i].second >= inter[j].first){
                graph[i].push_back(j);
            }
        }
    }


    // for (int i = 0; i < n; i++){
    //     for (int x : graph[i]) cout << x << " ";
    //     cout << endl;
    // }

    for (int i = 0; i < q; i++){
        int s, e;
        cin >> s >> e;
        s--, e--;

        queue<int> q;
        q.push(s);
        vector<int> tav(n, -1); 
        tav [s] = 0;
        while(!q.empty()){
            int pos = q.front();
            q.pop();
            for (int x : graph[pos]){
                if (tav[x] == -1){
                    tav[x] = tav[pos] + 1;
                    q.push(x);
                }
            }
        }
        if (tav[e] == -1) {
            cout << "impossible" << endl;
        }
        else cout << tav[e] << endl;
    }


    return 0;
}

/*

5 2
1 3
2 4
4 7
7 9
3 7
1 4
3 2

*/

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Execution timed out 1587 ms 9140 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 7 ms 340 KB Output is correct
4 Correct 5 ms 340 KB Output is correct
5 Correct 6 ms 340 KB Output is correct
6 Correct 12 ms 1104 KB Output is correct
7 Correct 20 ms 1912 KB Output is correct
8 Correct 21 ms 3012 KB Output is correct
9 Correct 83 ms 4308 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 7 ms 340 KB Output is correct
4 Correct 5 ms 340 KB Output is correct
5 Correct 6 ms 340 KB Output is correct
6 Correct 12 ms 1104 KB Output is correct
7 Correct 20 ms 1912 KB Output is correct
8 Correct 21 ms 3012 KB Output is correct
9 Correct 83 ms 4308 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 7 ms 340 KB Output is correct
13 Correct 6 ms 340 KB Output is correct
14 Correct 7 ms 344 KB Output is correct
15 Correct 10 ms 1028 KB Output is correct
16 Correct 19 ms 1876 KB Output is correct
17 Correct 20 ms 2992 KB Output is correct
18 Correct 88 ms 4308 KB Output is correct
19 Execution timed out 1581 ms 31404 KB Time limit exceeded
20 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 7 ms 340 KB Output is correct
4 Correct 5 ms 340 KB Output is correct
5 Correct 6 ms 340 KB Output is correct
6 Correct 12 ms 1104 KB Output is correct
7 Correct 20 ms 1912 KB Output is correct
8 Correct 21 ms 3012 KB Output is correct
9 Correct 83 ms 4308 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 8 ms 344 KB Output is correct
13 Correct 6 ms 336 KB Output is correct
14 Correct 6 ms 340 KB Output is correct
15 Correct 11 ms 1108 KB Output is correct
16 Correct 19 ms 1828 KB Output is correct
17 Correct 24 ms 2900 KB Output is correct
18 Correct 80 ms 4308 KB Output is correct
19 Execution timed out 1573 ms 8120 KB Time limit exceeded
20 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1568 ms 9164 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Execution timed out 1587 ms 9140 KB Time limit exceeded
3 Halted 0 ms 0 KB -