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Submission #593960

# Submission time Handle Problem Language Result Execution time Memory
593960 2022-07-11T18:23:59 Z CaroLinda Event Hopping (BOI22_events) C++14
40 / 100
 1500 ms 3056 KB 
#include <bits/stdc++.h>

//bad complexity to test idea

#define ll long long

const int MAXN = 1e5+10;
const int LOG = 20;

using namespace std;

int N, Q;
int S[MAXN], E[MAXN];
int dp[LOG][MAXN];


void findNxtArray(){
	vector<int> sweep(N);
	iota(sweep.begin(),sweep.end(), 1);

	sort(sweep.begin(),sweep.end(), [&](int a, int b){
		if(E[a] != E[b])
			return E[a] < E[b];
		return S[a] < S[b];
	});

	vector< pair<int,int> > s;

	for(auto &i : sweep){
		bool coloca = true;

		while(!s.empty()){
			int last = s.back().second;

			if(S[last] >= S[i]){
				s.pop_back();
			}
			else{
				if(E[last] == E[i]){
					coloca = false;
				}
				break;
			}
		}

		if(coloca)
			s.push_back(make_pair(E[i], i));

		int val = lower_bound(s.begin(),s.end(), make_pair(S[i],-1))->second;
		dp[0][i] = (val == i) ? -1 : val;
	}
}

bool isInside(int a, int b){
	return E[a] >= S[b] && E[a] <= E[b];
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);

	cin >> N >> Q;
	for(int i = 1; i <= N; i++)
		cin >> S[i] >> E[i];

	findNxtArray();

	for(int i = 1, a, b; i <= Q; i++){
		cin >> a >> b;

		int ans = 0;

		while(b != -1 && !isInside(a,b)){
			b = dp[0][b];
			ans++;
		}

		ans += (a != b);

		if(b == -1 || !isInside(a,b) ){
			cout << "impossible\n";
		}
		else cout << ans << "\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 1583 ms 3036 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 1 ms 340 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 0 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 1 ms 340 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 0 ms 340 KB Output is correct
10 Correct 1 ms 340 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 449 ms 928 KB Output is correct
20 Correct 1331 ms 980 KB Output is correct
21 Correct 598 ms 1228 KB Output is correct
22 Correct 20 ms 1236 KB Output is correct
23 Correct 26 ms 1052 KB Output is correct
24 Correct 20 ms 1168 KB Output is correct
25 Correct 54 ms 744 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 1 ms 340 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 0 ms 340 KB Output is correct
10 Correct 0 ms 340 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 134 ms 3036 KB Output is correct
20 Correct 75 ms 3028 KB Output is correct
21 Correct 32 ms 1872 KB Output is correct
22 Correct 44 ms 2540 KB Output is correct
23 Correct 32 ms 2992 KB Output is correct
24 Correct 31 ms 3056 KB Output is correct
25 Correct 20 ms 1876 KB Output is correct

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1584 ms 3028 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 1583 ms 3036 KB Time limit exceeded
3 Halted 0 ms 0 KB -