oj.uz

Submission #601101

# Submission time Handle Problem Language Result Execution time Memory
601101 2022-07-21T11:11:46 Z CSQ31 Event Hopping (BOI22_events) C++17
25 / 100
 1500 ms 2300 KB 
#include <bits/stdc++.h>
using namespace std;
#define all(a) a.begin(),a.end()
#define owo ios_base::sync_with_stdio(0);cin.tie(0);
const int MAXN = 1e5+1;
int s[MAXN],e[MAXN];
//fuck binlift how
//p(k,i) = min s if we jump backwards 2^k times
//p(k-1,i) = min of p(k-1),i<= x <= i ,p(k-1,x)
//yeesh but this n log^2n
//should pass maybe?
//1e5 * 18 * 18 = 3e7
int p[19][MAXN];
int main()
{
	owo
	int n,q;
	cin>>n>>q;
	vector<int>crd;
	for(int i=0;i<n;i++)cin>>s[i]>>e[i];
	for(int i=0;i<n;i++){
		crd.push_back(s[i]);
		crd.push_back(e[i]);
	}
	sort(all(crd));
	crd.resize(unique(all(crd)) - crd.begin());
	for(int i=0;i<n;i++){
		s[i] = lower_bound(all(crd),s[i]) - crd.begin()+1;
		e[i] = lower_bound(all(crd),e[i]) - crd.begin()+1;
	}
	//int m = crd.size();
	for(int i=0;i<n;i++){
		p[0][i] = i;
		for(int j=0;j<n;j++){
			if(s[i] <= e[j] && e[j] <= e[i]){
				if(s[j] < s[p[0][i]])p[0][i] = j;
			}	
		}
	}
	for(int i=1;i<=18;i++){
		for(int j=0;j<n;j++){
			p[i][j] = p[i-1][p[i-1][j]];	
		}
	}
	while(q--){
		int l,r;
		cin>>l>>r;
		l--;
		r--;
		if(l==r){
			cout<<0<<'\n';
			continue;
		}
		if(e[l] > e[r]){
			cout<<"impossible"<<'\n';
			continue;
		}
		if(s[r] <= e[l]){
			cout<<1<<'\n';
			continue;
		}
		int ans = 1; //one for actually arrivinf at l
		/*
		while(s[r] > e[l]){
			if(p[0][r] == r){
				ans = -1;
				break;
			}
			ans++;
			r = p[0][r];
		}*/
		for(int i=18;i>=0;i--){
			int v = p[i][r];
			if(s[v] > e[l]){
				r = v;
				ans+=(1<<i);
			}
		}
		ans++;
		if(r == p[0][r])ans=-1;	
		if(ans==-1)cout<<"impossible"<<'\n';
		else cout<<ans<<'\n';
	}
	
	
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Execution timed out 1594 ms 2208 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 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 3 ms 468 KB Output is correct
4 Correct 3 ms 468 KB Output is correct
5 Correct 4 ms 468 KB Output is correct
6 Correct 4 ms 492 KB Output is correct
7 Correct 5 ms 468 KB Output is correct
8 Correct 3 ms 468 KB Output is correct
9 Correct 2 ms 468 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 3 ms 468 KB Output is correct
4 Correct 3 ms 468 KB Output is correct
5 Correct 4 ms 468 KB Output is correct
6 Correct 4 ms 492 KB Output is correct
7 Correct 5 ms 468 KB Output is correct
8 Correct 3 ms 468 KB Output is correct
9 Correct 2 ms 468 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 468 KB Output is correct
13 Correct 4 ms 468 KB Output is correct
14 Correct 4 ms 468 KB Output is correct
15 Correct 5 ms 488 KB Output is correct
16 Correct 6 ms 468 KB Output is correct
17 Correct 3 ms 496 KB Output is correct
18 Correct 1 ms 468 KB Output is correct
19 Correct 130 ms 1364 KB Output is correct
20 Correct 98 ms 1356 KB Output is correct
21 Correct 103 ms 1756 KB Output is correct
22 Correct 111 ms 1756 KB Output is correct
23 Correct 119 ms 1640 KB Output is correct
24 Correct 95 ms 1752 KB Output is correct
25 Correct 101 ms 1336 KB Output is correct

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 3 ms 468 KB Output is correct
4 Correct 3 ms 468 KB Output is correct
5 Correct 4 ms 468 KB Output is correct
6 Correct 4 ms 492 KB Output is correct
7 Correct 5 ms 468 KB Output is correct
8 Correct 3 ms 468 KB Output is correct
9 Correct 2 ms 468 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 468 KB Output is correct
13 Correct 4 ms 468 KB Output is correct
14 Correct 4 ms 468 KB Output is correct
15 Correct 4 ms 468 KB Output is correct
16 Correct 5 ms 492 KB Output is correct
17 Correct 3 ms 468 KB Output is correct
18 Correct 1 ms 468 KB Output is correct
19 Execution timed out 1586 ms 2300 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 1578 ms 2260 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 340 KB Output is correct
2 Execution timed out 1594 ms 2208 KB Time limit exceeded
3 Halted 0 ms 0 KB -