Submission #583657

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
583657	2022-06-25T22:10:06 Z	tutis	Event Hopping (BOI22_events)	C++17	40 / 100	1500 ms	3724 KB

events

/*input
8 5
1 2
3 4
1 5
6 7
5 10
10 20
15 20
999999999 1000000000
1 6
1 7
2 4
3 3
5 8
*/
#include <bits/stdc++.h>
using namespace std;
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int N, Q;
	cin >> N >> Q;
	pair<pair<int, int>, int>A[N];
	for (int i = 0; i < N; i++)
	{
		cin >> A[i].first.second >> A[i].first.first;
		A[i].second = i;
	}
	sort(A, A + N);
	int p[N];
	for (int i = 0; i < N; i++)
		p[A[i].second] = i;
	int S[N], E[N];
	for (int i = 0; i < N; i++)
	{
		S[i] = A[i].first.second;
		E[i] = A[i].first.first;
	}
	for (int i = 0; i < N; i++)
	{
		S[i] = (lower_bound(E, E + N, S[i]) - E);
	}
	// int D[N][N];
	// for (int i = 0; i < N; i++)
	// 	for (int j = 0; j < N; j++)
	// 		D[i][j] = N + 10;
	vector<int>V;
	int pa[N];
	for (int j = 0; j < N; j++)
	{
		if (S[j] >= j)
		{
			pa[j] = j;
		}
		else
		{
			auto it = lower_bound(V.begin(), V.end(), S[j]);
			assert(it != V.end());
			pa[j] = *it;
		}
		while (!V.empty() && S[V.back()] >= S[j])
			V.pop_back();
		V.push_back(j);
	}
	while (Q--)
	{
		int s, t;
		cin >> s >> t;
		s = p[s - 1];
		t = p[t - 1];
		if (s == t)
		{
			cout << "0\n";
		}
		else {
			if (A[t].first.second <= A[s].first.first && A[s].first.first <= A[t].first.first)
				cout << "1\n";
			else {
				if (s >= t)
				{
					cout << "impossible\n";
					continue;
				}
				int a = 1;
				while (true)
				{
					if (s >= S[t])
					{
						cout << a << "\n";
						break;
					}
					if (pa[t] == t)
					{
						cout << "impossible\n";
						break;
					}
					t = pa[t];
					a++;
				}
				// int k = D[t][s];
				// if (k > N)
				// 	cout << "impossible\n";
				// else
				// 	cout << k << "\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	1591 ms	3712 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	2 ms	336 KB	Output is correct
4	Correct	1 ms	340 KB	Output is correct
5	Correct	1 ms	340 KB	Output is correct
6	Correct	1 ms	340 KB	Output is correct
7	Correct	1 ms	340 KB	Output is correct
8	Correct	1 ms	340 KB	Output is correct
9	Correct	1 ms	340 KB	Output is correct

Subtask #3

15.0 / 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	2 ms	336 KB	Output is correct
4	Correct	1 ms	340 KB	Output is correct
5	Correct	1 ms	340 KB	Output is correct
6	Correct	1 ms	340 KB	Output is correct
7	Correct	1 ms	340 KB	Output is correct
8	Correct	1 ms	340 KB	Output is correct
9	Correct	1 ms	340 KB	Output is correct
10	Correct	0 ms	212 KB	Output is correct
11	Correct	0 ms	212 KB	Output is correct
12	Correct	1 ms	340 KB	Output is correct
13	Correct	1 ms	340 KB	Output is correct
14	Correct	1 ms	340 KB	Output is correct
15	Correct	1 ms	340 KB	Output is correct
16	Correct	1 ms	340 KB	Output is correct
17	Correct	1 ms	340 KB	Output is correct
18	Correct	1 ms	340 KB	Output is correct
19	Correct	400 ms	848 KB	Output is correct
20	Correct	1146 ms	976 KB	Output is correct
21	Correct	230 ms	1240 KB	Output is correct
22	Correct	20 ms	1236 KB	Output is correct
23	Correct	20 ms	1108 KB	Output is correct
24	Correct	19 ms	1032 KB	Output is correct
25	Correct	42 ms	724 KB	Output is correct

Subtask #4

15.0 / 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	2 ms	336 KB	Output is correct
4	Correct	1 ms	340 KB	Output is correct
5	Correct	1 ms	340 KB	Output is correct
6	Correct	1 ms	340 KB	Output is correct
7	Correct	1 ms	340 KB	Output is correct
8	Correct	1 ms	340 KB	Output is correct
9	Correct	1 ms	340 KB	Output is correct
10	Correct	0 ms	212 KB	Output is correct
11	Correct	0 ms	212 KB	Output is correct
12	Correct	1 ms	340 KB	Output is correct
13	Correct	1 ms	340 KB	Output is correct
14	Correct	1 ms	340 KB	Output is correct
15	Correct	1 ms	340 KB	Output is correct
16	Correct	1 ms	340 KB	Output is correct
17	Correct	1 ms	340 KB	Output is correct
18	Correct	1 ms	340 KB	Output is correct
19	Correct	64 ms	3652 KB	Output is correct
20	Correct	44 ms	3652 KB	Output is correct
21	Correct	41 ms	3012 KB	Output is correct
22	Correct	45 ms	3412 KB	Output is correct
23	Correct	29 ms	3028 KB	Output is correct
24	Correct	35 ms	3680 KB	Output is correct
25	Correct	25 ms	3024 KB	Output is correct

Subtask #5

0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Execution timed out	1579 ms	3724 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	1591 ms	3712 KB	Time limit exceeded
3	Halted	0 ms	0 KB	-