#include <bits/stdc++.h>
#define N 200005
using namespace std;
int n;
set<int> del[2];
set<pair<int,int>> bridge[2];
bool can(int x,int y,int type){
if(x > n){
return can(2*n+1-x,2*n+1-y,!type);
}
if(y <= n){
if(x <= y && y <= *del[type].lower_bound(x))return 1;
if(y <= x && bridge[type].size() && bridge[type].lower_bound({y+1,0}) != bridge[type].begin()){
if(can(x,prev(bridge[type].lower_bound({y+1,0}))->second,type))return 1;
}
}
else{
if(!(bridge[type].empty() || bridge[type].rbegin()->first < x || bridge[type].rbegin()->second < y)){
int l = x,r = bridge[type].rbegin()->first;
while(l < r){
int m = (l + r)/2;
auto it = bridge[type].lower_bound({m,0});
if(it->second < y){
l = m+1;
}
else r = m;
}
auto it = bridge[type].lower_bound({l,0});
if(can(x,it->first,type)&&can(it->second,y,type))return 1;
}
}
return 0;
}
void solve(){
int m;
cin >> n >> m;
del[0].insert(2*n+5);
del[1].insert(2*n+5);
while(m--){
char type;
int x,y;
cin >> type;
cin >> x >> y;
if(type == 'A'){
if(y < x)swap(x,y);
bridge[0].insert({x,y});
bridge[1].insert({2*n+1 -y,2*n+1-x});
}
if(type == 'B'){
if(y < x)swap(x,y);
del[0].insert(x);
del[1].insert(2*n+1-y);
}
if(type == 'Q'){
cout << (can(x,y,0)?"DA":"NE") << "\n";
}
}
}
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
#ifdef Local
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
#endif
int t=1;
//cin>>t;
while(t--){
solve();
}
#ifdef Local
cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
#endif
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
208 KB |
Output is correct |
2 |
Incorrect |
1 ms |
208 KB |
Output isn't correct |
3 |
Incorrect |
1 ms |
336 KB |
Output isn't correct |
4 |
Incorrect |
1 ms |
336 KB |
Output isn't correct |
5 |
Correct |
1 ms |
336 KB |
Output is correct |
6 |
Correct |
1 ms |
336 KB |
Output is correct |
7 |
Incorrect |
255 ms |
14436 KB |
Output isn't correct |
8 |
Incorrect |
377 ms |
14344 KB |
Output isn't correct |
9 |
Incorrect |
278 ms |
15940 KB |
Output isn't correct |
10 |
Incorrect |
350 ms |
15872 KB |
Output isn't correct |