#include <bits/stdc++.h>
using namespace std;
int32_t main(){
ios::sync_with_stdio(0);
cin.tie(0);
int n,m;
cin >> n >> m;
pair<int,int> arr[n];
for(int i=0; i<n; i++) cin >> arr[i].first >> arr[i].second;
vector<pair<int,pair<int,int> > > vert;
for(int i=0; i<n-1; i++){
if(arr[i].first==arr[i+1].first) vert.push_back({arr[i].first,{arr[i].second,arr[i+1].second}});
}
if(arr[0].first==arr[n-1].first) vert.push_back({arr[0].first,{arr[0].second,arr[n-1].second}});
set<pair<int,int> > odd,even,all;
set<pair<int,int> >::iterator it;
sort(vert.begin(),vert.end());
int ans=0,bad=0;
for(int o=0; o<(int)vert.size(); o++){
pair<int,pair<int,int> > i=vert[o];
pair<int,int> ln=i.second;
if(ln.second<ln.first) swap(ln.second,ln.first);
it=all.upper_bound({ln.first,1e9});
if(it!=all.begin()) it--;
if(it!=all.end()&&it->first<=ln.first&&it->second>=ln.second){
pair<int,int> tmp=*it;
all.erase(it);
if((it->second-it->first)%2) bad--;
if(tmp.first<ln.first) all.insert({tmp.first,ln.first});
if(ln.second<tmp.second) all.insert({ln.second,tmp.second});
if((ln.first-tmp.first)%2) bad++;
if((tmp.second-ln.second)%2) bad++;
}
else{
it=all.lower_bound(ln);
if(it!=all.end()&&it->first==ln.second){
ln.second=it->second;
if((it->second-it->first)%2) bad--;
all.erase(it);
}
it=all.lower_bound(ln);
if(it!=all.begin()) it--;
if(it!=all.end()&&it->second==ln.first){
ln.first=it->first;
if((it->second-it->first)%2) bad--;
all.erase(it);
}
all.insert(ln);
if((ln.second-ln.first)%2) bad++;
}
if(o==(int)vert.size()-1||vert[o+1].first!=vert[o].first){
if(bad>0){
cout << ans;
return 0;
}
}
bool got=false;
it=odd.lower_bound(ln);
if(it!=odd.begin()) it--;
for(;it!=odd.end();it++){
if(it->second<=ln.first) continue;
if(it->first>=ln.second) break;
if(i.first%2==0){
cout << ans;
return 0;
}
got=true;
pair<int,int> tmp=*it;
odd.erase(it);
odd.insert({max(tmp.first,ln.first),min(tmp.second,ln.second)});
}
it=even.lower_bound(ln);
if(it!=even.begin()) it--;
for(;it!=even.end();it++){
if(it->second<=ln.first) continue;
if(it->first>=ln.second) break;
if(i.first%2==1){
cout << ans;
return 0;
}
got=true;
pair<int,int> tmp=*it;
even.erase(it);
even.insert({max(tmp.first,ln.first),min(tmp.second,ln.second)});
}
if(!got){
if(i.first%2==1) odd.insert(ln);
else even.insert(ln);
}
if(i.first%2==1&&even.empty()){
if(o==(int)vert.size()-1||vert[o+1].first!=vert[o].first){
if(vert[o+1].first%2==1) ans=vert[o+1].first;
else ans=vert[o+1].first-1;
}
}
else if(i.first%2==0&&odd.empty()){
if(o==(int)vert.size()-1||vert[o+1].first!=vert[o].first){
if(vert[o+1].first%2==0) ans=vert[o+1].first;
else ans=vert[o+1].first-1;
}
}
}
cout << ans;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
6 ms |
1184 KB |
Output is correct |
3 |
Correct |
47 ms |
6856 KB |
Output is correct |
4 |
Incorrect |
37 ms |
4044 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
24 ms |
3540 KB |
Output is correct |
6 |
Correct |
41 ms |
3664 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Incorrect |
51 ms |
692 KB |
Output isn't correct |
11 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Incorrect |
25 ms |
4168 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
45 ms |
6856 KB |
Output is correct |
2 |
Incorrect |
29 ms |
4040 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |