#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll MOD = 1000000007;
const string ny[2] = {"No", "Yes"};
#define x first
#define y second
vector<vector<ll>> G(200000);
vector<vector<ll>> P(24,vector<ll>(200000,0));
vector<ll> v(200000,0);
void dfs(ll node, ll p,ll d)
{
if(v[node]!=0) return;
v[node]=d;
P[0][node]=p;
for(int i=1; i<24; i++)
P[i][node]=P[i-1][P[i-1][node]];
for(auto i:G[node])
dfs(i,node,d+1);
}
ll Padre_A_Distancia_D(ll a, ll d)
{
for(int i=23; i>=0; i--)
if((d&(1<<i))!=0)
a=P[i][a];
return a;
}
ll lca(ll a, ll b)
{
ll cont=0;
if(v[a]<v[b]) return 1e9;
cont+=v[a]-v[b];
a=Padre_A_Distancia_D(a,v[a]-v[b]);
if(a==b) return cont;
else return 1e9;
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
ll n,q;
cin>>n>>q;
v.resize(n+2);
vector<pair<ll,ll>> cad;
vector<pair<ll,ll>> input;input.push_back({0,0});
for(int i=1; i<=n; i++)
{
ll a,b;
cin>>a>>b;
input.push_back({a,b});
cad.push_back({a,i});
cad.push_back({b,i});
}
sort(cad.begin(),cad.end());
set<ll> s;
for(int i=0; i<cad.size(); i++)
{
vector<ll> temp,temp2;
ll a=i;
while(i<cad.size()&&cad[a].x==cad[i].x){
temp.push_back(cad[i].y);
i++;
}
i--;
for(auto j:temp)
{
if(s.find(j)!=s.end())
temp2.push_back(j);
else s.insert(j);
}
for(auto j:temp2) for(auto k:s) if(j!=k)G[j].push_back(k);
for(auto j:temp2) if(s.find(j)!=s.end()) s.erase(j);
}
vector<ll> asdf(n+2,0);
for(int i=1; i<=n; i++)
{
for(auto j:G[i])
{
asdf[j]++;
}
}
for(int i=1; i<=n; i++)
if(asdf[i]==0)
{
dfs(i,0,1);
}
for(int i=0; i<q; i++)
{
ll a,b;
cin>>a>>b;
if(a==b){cout<<0<<"\n";continue;}
else if(input[a].y==input[b].y)
{
cout<<1<<"\n";
continue;
}
a=lca(b,a);
if(a==1e9) cout<<"impossible"<<"\n";
else cout<<a<<"\n";
}
return 0;
}
Compilation message
events.cpp: In function 'int main()':
events.cpp:56:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
56 | for(int i=0; i<cad.size(); i++)
| ~^~~~~~~~~~~
events.cpp:60:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
60 | while(i<cad.size()&&cad[a].x==cad[i].x){
| ~^~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
17 ms |
44124 KB |
Output is correct |
2 |
Correct |
94 ms |
58636 KB |
Output is correct |
3 |
Correct |
104 ms |
59444 KB |
Output is correct |
4 |
Correct |
133 ms |
58676 KB |
Output is correct |
5 |
Incorrect |
103 ms |
58440 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
17 ms |
44124 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
17 ms |
44124 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
17 ms |
44124 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
94 ms |
58984 KB |
Output is correct |
2 |
Correct |
110 ms |
59444 KB |
Output is correct |
3 |
Correct |
111 ms |
58672 KB |
Output is correct |
4 |
Correct |
74 ms |
53556 KB |
Output is correct |
5 |
Correct |
105 ms |
56780 KB |
Output is correct |
6 |
Incorrect |
220 ms |
103160 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
17 ms |
44124 KB |
Output is correct |
2 |
Correct |
94 ms |
58636 KB |
Output is correct |
3 |
Correct |
104 ms |
59444 KB |
Output is correct |
4 |
Correct |
133 ms |
58676 KB |
Output is correct |
5 |
Incorrect |
103 ms |
58440 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |