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Submission #577742

# Submission time Handle Problem Language Result Execution time Memory
577742 2022-06-15T08:32:03 Z vanic Event Hopping (BOI22_events) C++14
10 / 100
 1500 ms 38464 KB 
#include <cstdio>
#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));
	vector < int > q1, q2;
	q1.push_back(a[x].second+pot);
	dist[a[x].second+pot]=0;
	d[x]=0;
	int tren=0;
	while(!q1.empty()){
		while(!q1.empty()){
			x=q1.back();
			q1.pop_back();
			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_back(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_back(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:80:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   80 |  scanf("%d%d", &n, &q);
      |  ~~~~~^~~~~~~~~~~~~~~~
events.cpp:82:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |   scanf("%d%d", &a[i].first, &a[i].second);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
events.cpp:105:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  105 |   scanf("%d%d", &x, &y);
      |   ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 16084 KB Output is correct
2 Execution timed out 1582 ms 26312 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 16072 KB Output is correct
2 Correct 18 ms 16012 KB Output is correct
3 Correct 31 ms 16160 KB Output is correct
4 Correct 24 ms 16052 KB Output is correct
5 Correct 22 ms 16052 KB Output is correct
6 Correct 21 ms 16084 KB Output is correct
7 Correct 24 ms 16212 KB Output is correct
8 Correct 23 ms 16212 KB Output is correct
9 Correct 20 ms 16092 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 16072 KB Output is correct
2 Correct 18 ms 16012 KB Output is correct
3 Correct 31 ms 16160 KB Output is correct
4 Correct 24 ms 16052 KB Output is correct
5 Correct 22 ms 16052 KB Output is correct
6 Correct 21 ms 16084 KB Output is correct
7 Correct 24 ms 16212 KB Output is correct
8 Correct 23 ms 16212 KB Output is correct
9 Correct 20 ms 16092 KB Output is correct
10 Correct 17 ms 16016 KB Output is correct
11 Correct 16 ms 15956 KB Output is correct
12 Correct 23 ms 16172 KB Output is correct
13 Correct 28 ms 16136 KB Output is correct
14 Correct 24 ms 16176 KB Output is correct
15 Correct 27 ms 16084 KB Output is correct
16 Correct 24 ms 16372 KB Output is correct
17 Correct 24 ms 16144 KB Output is correct
18 Correct 20 ms 16084 KB Output is correct
19 Execution timed out 1587 ms 17236 KB Time limit exceeded
20 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 16072 KB Output is correct
2 Correct 18 ms 16012 KB Output is correct
3 Correct 31 ms 16160 KB Output is correct
4 Correct 24 ms 16052 KB Output is correct
5 Correct 22 ms 16052 KB Output is correct
6 Correct 21 ms 16084 KB Output is correct
7 Correct 24 ms 16212 KB Output is correct
8 Correct 23 ms 16212 KB Output is correct
9 Correct 20 ms 16092 KB Output is correct
10 Correct 16 ms 15956 KB Output is correct
11 Correct 16 ms 16004 KB Output is correct
12 Correct 24 ms 16084 KB Output is correct
13 Correct 22 ms 16096 KB Output is correct
14 Correct 22 ms 16176 KB Output is correct
15 Correct 21 ms 16116 KB Output is correct
16 Correct 26 ms 16276 KB Output is correct
17 Correct 29 ms 16212 KB Output is correct
18 Correct 29 ms 16072 KB Output is correct
19 Correct 1014 ms 26152 KB Output is correct
20 Correct 738 ms 26224 KB Output is correct
21 Correct 703 ms 26968 KB Output is correct
22 Correct 399 ms 26188 KB Output is correct
23 Correct 1466 ms 38464 KB Output is correct
24 Execution timed out 1585 ms 37572 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 1566 ms 26188 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 16084 KB Output is correct
2 Execution timed out 1582 ms 26312 KB Time limit exceeded
3 Halted 0 ms 0 KB -