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Submission #577696

# Submission time Handle Problem Language Result Execution time Memory
577696 2022-06-15T08:11:15 Z vanic Event Hopping (BOI22_events) C++14
10 / 100
 1500 ms 74220 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=18, 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].first);
		s.insert(a[i].second);
	}
	int br=0;
	for(auto it=s.begin(); it!=s.end(); it++){
		m[*it]=br;
		br++;
	}
	for(int i=1; i<=n; i++){
		a[i]={m[a[i].first], 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:104:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  104 |   scanf("%d%d", &x, &y);
      |   ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 32 ms 31564 KB Output is correct
2 Execution timed out 1590 ms 41636 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 33 ms 31348 KB Output is correct
2 Correct 32 ms 31332 KB Output is correct
3 Correct 43 ms 31532 KB Output is correct
4 Correct 39 ms 31616 KB Output is correct
5 Correct 42 ms 31548 KB Output is correct
6 Correct 41 ms 31580 KB Output is correct
7 Correct 52 ms 31688 KB Output is correct
8 Correct 44 ms 31700 KB Output is correct
9 Correct 39 ms 31476 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 33 ms 31348 KB Output is correct
2 Correct 32 ms 31332 KB Output is correct
3 Correct 43 ms 31532 KB Output is correct
4 Correct 39 ms 31616 KB Output is correct
5 Correct 42 ms 31548 KB Output is correct
6 Correct 41 ms 31580 KB Output is correct
7 Correct 52 ms 31688 KB Output is correct
8 Correct 44 ms 31700 KB Output is correct
9 Correct 39 ms 31476 KB Output is correct
10 Correct 36 ms 31444 KB Output is correct
11 Correct 34 ms 31460 KB Output is correct
12 Correct 46 ms 31544 KB Output is correct
13 Correct 49 ms 31440 KB Output is correct
14 Correct 40 ms 31568 KB Output is correct
15 Correct 52 ms 31544 KB Output is correct
16 Correct 45 ms 31684 KB Output is correct
17 Correct 42 ms 31700 KB Output is correct
18 Correct 39 ms 31476 KB Output is correct
19 Execution timed out 1595 ms 32664 KB Time limit exceeded
20 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 33 ms 31348 KB Output is correct
2 Correct 32 ms 31332 KB Output is correct
3 Correct 43 ms 31532 KB Output is correct
4 Correct 39 ms 31616 KB Output is correct
5 Correct 42 ms 31548 KB Output is correct
6 Correct 41 ms 31580 KB Output is correct
7 Correct 52 ms 31688 KB Output is correct
8 Correct 44 ms 31700 KB Output is correct
9 Correct 39 ms 31476 KB Output is correct
10 Correct 36 ms 31384 KB Output is correct
11 Correct 32 ms 31428 KB Output is correct
12 Correct 42 ms 31444 KB Output is correct
13 Correct 40 ms 31508 KB Output is correct
14 Correct 40 ms 31552 KB Output is correct
15 Correct 40 ms 31488 KB Output is correct
16 Correct 44 ms 31716 KB Output is correct
17 Correct 55 ms 31796 KB Output is correct
18 Correct 40 ms 31464 KB Output is correct
19 Correct 1318 ms 41612 KB Output is correct
20 Correct 831 ms 41736 KB Output is correct
21 Correct 907 ms 46924 KB Output is correct
22 Correct 536 ms 45572 KB Output is correct
23 Execution timed out 1582 ms 74220 KB Time limit exceeded
24 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1596 ms 41548 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 32 ms 31564 KB Output is correct
2 Execution timed out 1590 ms 41636 KB Time limit exceeded
3 Halted 0 ms 0 KB -