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Submission #722641

# Submission time Handle Problem Language Result Execution time Memory
722641 2023-04-12T13:41:29 Z dxz05 Event Hopping (BOI22_events) C++17
10 / 100
 1500 ms 3400 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;

int f[N];
int l[N], r[N];

bool can_switch(int i, int j){
    return l[j] <= r[i] && r[i] <= r[j];
}

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

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

    for (int i = 0; i < n; i++){
        f[i] = -1;
        for (int j = 0; j < n; j++){
            if (i == j) continue;
            if (can_switch(j, i)){
                if (f[i] == -1 || l[j] < l[f[i]]) f[i] = j;
            }
        }
        if (l[f[i]] >= l[i]) f[i] = -1;
    }

    while (q--){
        int x, y;
        cin >> x >> y;
        --x, --y;
        if (x == y){
            cout << 0 << endl;
            continue;
        }
        if (can_switch(x, y)){
            cout << 1 << endl;
            continue;
        }
        int cnt = 1;
        while (l[y] > r[x]){
            y = f[y];
            cnt++;
            if (y == -1) break;
        }

        if (y != -1 && can_switch(x, y)){
            cout << cnt << endl;
        } else {
            cout << "impossible" << 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 0 ms 212 KB Output is correct
2 Execution timed out 1572 ms 1452 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 1 ms 212 KB Output is correct
3 Correct 4 ms 340 KB Output is correct
4 Correct 3 ms 340 KB Output is correct
5 Correct 3 ms 336 KB Output is correct
6 Correct 5 ms 340 KB Output is correct
7 Correct 6 ms 340 KB Output is correct
8 Correct 4 ms 360 KB Output is correct
9 Correct 2 ms 344 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 1 ms 212 KB Output is correct
3 Correct 4 ms 340 KB Output is correct
4 Correct 3 ms 340 KB Output is correct
5 Correct 3 ms 336 KB Output is correct
6 Correct 5 ms 340 KB Output is correct
7 Correct 6 ms 340 KB Output is correct
8 Correct 4 ms 360 KB Output is correct
9 Correct 2 ms 344 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 4 ms 340 KB Output is correct
13 Correct 4 ms 348 KB Output is correct
14 Correct 3 ms 340 KB Output is correct
15 Correct 4 ms 340 KB Output is correct
16 Correct 5 ms 344 KB Output is correct
17 Correct 4 ms 364 KB Output is correct
18 Correct 2 ms 340 KB Output is correct
19 Correct 766 ms 1788 KB Output is correct
20 Execution timed out 1562 ms 2116 KB Time limit exceeded
21 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 1 ms 212 KB Output is correct
3 Correct 4 ms 340 KB Output is correct
4 Correct 3 ms 340 KB Output is correct
5 Correct 3 ms 336 KB Output is correct
6 Correct 5 ms 340 KB Output is correct
7 Correct 6 ms 340 KB Output is correct
8 Correct 4 ms 360 KB Output is correct
9 Correct 2 ms 344 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 4 ms 340 KB Output is correct
13 Correct 4 ms 344 KB Output is correct
14 Correct 3 ms 336 KB Output is correct
15 Correct 5 ms 344 KB Output is correct
16 Correct 6 ms 372 KB Output is correct
17 Correct 4 ms 340 KB Output is correct
18 Correct 3 ms 340 KB Output is correct
19 Execution timed out 1567 ms 3400 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 1546 ms 1492 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 1572 ms 1452 KB Time limit exceeded
3 Halted 0 ms 0 KB -