#include <bits/stdc++.h>
using namespace std;
#define pb push_back
typedef long long ll;
struct Event {
int S;
int E;
int i;
};
bool operator<(Event A, Event B) {
return A.S<B.S;
}
int N, a, b, Q;
map<int, set<Event>> vegek;
vector<int> evts;
vector<int> starts;
map<int, vector<int>> graf;
vector<int> hely;
map<int, map<int, int>> tav;
int main() {
ios::sync_with_stdio(false);cin.tie(nullptr);
cin>>N>>Q;
hely.resize(N+1);
for(int i=0; i<N; i++) {
cin>>a>>b;
starts.pb(a);
if(vegek.find(b)==vegek.end()) {
evts.pb(b);
}
vegek[b].insert({a, b, i+1});
}
sort(evts.begin(), evts.end(), [](int a, int b) {return vegek[a].begin()->S<vegek[b].begin()->S;});
for(int i=0; i<N; i++) {
for(const Event &evt : vegek[evts[i]]) hely[evt.i]=evts[i];
for(int j=i+1; j<N&&vegek[evts[j]].begin()->S<=vegek[evts[i]].begin()->E; j++) {
if(vegek[evts[j]].begin()->E<vegek[evts[i]].begin()->E) continue;
graf[evts[j]].pb(evts[i]);
}
}
for(int i=0; i<N; i++) {
tav[evts[i]][evts[i]]=0;
}
for(int i=0; i<N; i++) {
int x=evts[i];
for(int be : graf[x]) {
for(auto &beBe : tav[be]) {
if(tav[x].find(beBe.first)!=tav[x].end()) {
if(tav[x][beBe.first]>beBe.second+1) {
tav[x][beBe.first]=beBe.second+1;
//honnan[x][beBe.first]=be;
}
}
else {
tav[x][beBe.first]=beBe.second+1;
//honnan[x][beBe.first]=be;
}
}
}
}
for(int i=0;i<Q;i++){
cin>>a>>b;
auto it = tav[hely[b]].find(hely[a]);
if(it==tav[hely[b]].end()) {
cout<<"impossible\n";
}
else {
//cout<<"x"<<vegek[hely[b]].begin()->S<<"y"<<starts[b-1]<<endl;
if(starts[b-1]==vegek[hely[b]].begin()->S) {
cout<<it->second<<'\n';
}
else {
cout<<it->second+1<<"\n";
}
}
}
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Execution timed out |
1597 ms |
302296 KB |
Time limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
320 KB |
Output is correct |
3 |
Correct |
91 ms |
24332 KB |
Output is correct |
4 |
Correct |
47 ms |
12360 KB |
Output is correct |
5 |
Correct |
91 ms |
24104 KB |
Output is correct |
6 |
Execution timed out |
1577 ms |
1244 KB |
Time limit exceeded |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
320 KB |
Output is correct |
3 |
Correct |
91 ms |
24332 KB |
Output is correct |
4 |
Correct |
47 ms |
12360 KB |
Output is correct |
5 |
Correct |
91 ms |
24104 KB |
Output is correct |
6 |
Execution timed out |
1577 ms |
1244 KB |
Time limit exceeded |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
320 KB |
Output is correct |
3 |
Correct |
91 ms |
24332 KB |
Output is correct |
4 |
Correct |
47 ms |
12360 KB |
Output is correct |
5 |
Correct |
91 ms |
24104 KB |
Output is correct |
6 |
Execution timed out |
1577 ms |
1244 KB |
Time limit exceeded |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
1541 ms |
262236 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Execution timed out |
1597 ms |
302296 KB |
Time limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |