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Submission #577703

# Submission time Handle Problem Language Result Execution time Memory
577703 2022-06-15T08:15:09 Z vanic Event Hopping (BOI22_events) C++14
10 / 100
 1500 ms 37940 KB 
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <cstring>
#include <queue>
 
using namespace std;
 
const int maxn=1e5+5, Log=17, pot=(1<<Log);
 
vector < int > svi;
 
void query(int L, int D, int x, int l, int d){
	if(L>=l && D<=d){
		svi.push_back(x);
		return;
	}
	if((L+D)/2>=l){
		query(L, (L+D)/2, x*2, l, d);
	}
	if((L+D)/2+1<=d){
		query((L+D)/2+1, D, x*2+1, l, d);
	}
}
 
 
pair < int, int > a[maxn];
set < int > s;
map < int, int > m;
int dist[pot*2];
int d[maxn];
vector < pair < int, int > >  ms[pot*2];
 
void precompute(){
	for(int i=2; i<pot*2; i++){
		ms[i].push_back({i/2, 0});
	}
}
 
void bfs(int x){
	memset(dist, -1, sizeof(dist));
	memset(d, -1, sizeof(d));
	queue < int > q1, q2;
	q1.push(a[x].second+pot);
	dist[a[x].second+pot]=0;
	d[x]=0;
	int tren=0;
	while(!q1.empty()){
		while(!q1.empty()){
			x=q1.front();
			q1.pop();
			for(int i=0; i<(int)ms[x].size(); i++){
				if(ms[x][i].second){
					if(dist[ms[x][i].first]==-1){
						dist[ms[x][i].first]=tren+1;
						q2.push(ms[x][i].first);
					}
					if(d[ms[x][i].second]==-1){
						d[ms[x][i].second]=tren+1;
					}
				}
				else{
					if(dist[ms[x][i].first]==-1){
						dist[ms[x][i].first]=tren;
						q1.push(ms[x][i].first);
					}
				}
			}
		}
		swap(q1, q2);
		tren++;
	}
}
 
int main(){
	precompute();
	int n, q;
	scanf("%d%d", &n, &q);
	for(int i=1; i<=n; i++){
		scanf("%d%d", &a[i].first, &a[i].second);
		s.insert(a[i].second);
	}
	int br=0;
	
	for(auto it=s.begin(); it!=s.end(); it++){
		m[*it]=br;
		br++;
	}
	set < int >::iterator it;
	for(int i=1; i<=n; i++){
		it=s.lower_bound(a[i].first);
		a[i]={m[*it], m[a[i].second]};
//		cout << a[i].first << ' ' << a[i].second << endl;
		query(0, pot-1, 1, a[i].first, a[i].second);
		while(!svi.empty()){
//			cout << "moji " << svi.back() << endl;
			ms[svi.back()].push_back({a[i].second+pot, i});
			svi.pop_back();
		}
	}
	int x, y;
	for(int i=0; i<q; i++){
		scanf("%d%d", &x, &y);
		bfs(x);
		if(d[y]==-1){
			printf("impossible\n");
		}
		else{
			printf("%d\n", d[y]);
		}
	}
	return 0;
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:81:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |  scanf("%d%d", &n, &q);
      |  ~~~~~^~~~~~~~~~~~~~~~
events.cpp:83:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |   scanf("%d%d", &a[i].first, &a[i].second);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
events.cpp:106:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  106 |   scanf("%d%d", &x, &y);
      |   ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 15956 KB Output is correct
2 Execution timed out 1591 ms 26104 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 15956 KB Output is correct
2 Correct 19 ms 16040 KB Output is correct
3 Correct 26 ms 16168 KB Output is correct
4 Correct 27 ms 16176 KB Output is correct
5 Correct 26 ms 16116 KB Output is correct
6 Correct 23 ms 16084 KB Output is correct
7 Correct 27 ms 16252 KB Output is correct
8 Correct 32 ms 16252 KB Output is correct
9 Correct 26 ms 16084 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 15956 KB Output is correct
2 Correct 19 ms 16040 KB Output is correct
3 Correct 26 ms 16168 KB Output is correct
4 Correct 27 ms 16176 KB Output is correct
5 Correct 26 ms 16116 KB Output is correct
6 Correct 23 ms 16084 KB Output is correct
7 Correct 27 ms 16252 KB Output is correct
8 Correct 32 ms 16252 KB Output is correct
9 Correct 26 ms 16084 KB Output is correct
10 Correct 21 ms 16076 KB Output is correct
11 Correct 19 ms 16000 KB Output is correct
12 Correct 27 ms 16168 KB Output is correct
13 Correct 26 ms 16060 KB Output is correct
14 Correct 25 ms 16084 KB Output is correct
15 Correct 23 ms 16052 KB Output is correct
16 Correct 26 ms 16204 KB Output is correct
17 Correct 26 ms 16220 KB Output is correct
18 Correct 28 ms 16084 KB Output is correct
19 Execution timed out 1581 ms 17228 KB Time limit exceeded
20 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 15956 KB Output is correct
2 Correct 19 ms 16040 KB Output is correct
3 Correct 26 ms 16168 KB Output is correct
4 Correct 27 ms 16176 KB Output is correct
5 Correct 26 ms 16116 KB Output is correct
6 Correct 23 ms 16084 KB Output is correct
7 Correct 27 ms 16252 KB Output is correct
8 Correct 32 ms 16252 KB Output is correct
9 Correct 26 ms 16084 KB Output is correct
10 Correct 23 ms 15956 KB Output is correct
11 Correct 17 ms 15956 KB Output is correct
12 Correct 25 ms 16172 KB Output is correct
13 Correct 23 ms 16156 KB Output is correct
14 Correct 25 ms 16116 KB Output is correct
15 Correct 25 ms 16172 KB Output is correct
16 Correct 28 ms 16212 KB Output is correct
17 Correct 28 ms 16148 KB Output is correct
18 Correct 27 ms 16088 KB Output is correct
19 Correct 1388 ms 26224 KB Output is correct
20 Correct 675 ms 26352 KB Output is correct
21 Correct 668 ms 26912 KB Output is correct
22 Correct 462 ms 26312 KB Output is correct
23 Correct 1291 ms 37940 KB Output is correct
24 Execution timed out 1595 ms 37580 KB Time limit exceeded
25 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1574 ms 26308 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 15956 KB Output is correct
2 Execution timed out 1591 ms 26104 KB Time limit exceeded
3 Halted 0 ms 0 KB -