#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
class UN{
public:
vector<int>P;
vector<list<int> >from;
UN(int n){P.resize(n);from.resize(n);for(int i=0;i<n;i++)P[i]=i,from[i].push_back(i);}
int F(int X){return X==P[X]?X:P[X]=F(P[X]);}
bool ch(int X,int Y)
{
if(F(X)!=F(Y))
{
P[P[X]]=P[Y];
// puts("ABA");
from[Y].insert(from[Y].end(),from[X].begin(),from[X].end());
// puts("AMA");
from[X].clear();
// puts("AEA");
return 1;
}
return 0;
}
};
vector<vector<int> >V;
vector<int>ST,NST,VC;
bitset<100000>ch,IS;
int N,M;
int main()
{
// freopen("in.txt","r",stdin);
ios::sync_with_stdio(0);
cin.tie(0);
cin>>N>>M;
UN tr(N);
V.resize(N);
VC.resize(N);
for(int i=0;i<M;i++)
{
int T,O;
cin>>T>>O;T--,O--;
V[T].push_back(O);
}
for(int i=0;i<N;i++)
if(V[i].size()>=2)
{
for(auto&I:V[i])tr.ch(I,V[i][0]),IS.set(I);
ch.set(i);
}
for(int i=0;i<N;i++)
{
// printf("A");
if(V[i].size()==1&&IS.test(i))
ST.push_back(i);
// printf("B");
}
while(ST.size())
{
NST.resize(0);
// puts("AA");
for(auto&J:ST)for(auto&I:V[J])
{
// puts("BC");
if(V[I].size()==1)
{
if(!IS.test(I))NST.push_back(I);
tr.ch(I,J),IS.set(I);
}
else if(V[I].size()>1&&tr.ch(I,J)){IS.set(I);for(auto&K:tr.from[tr.F(I)])tr.ch(I,K),tr.ch(V[I][0],K);}
}
// puts("BB");
swap(ST,NST);
}
for(int i=0;i<N;i++)VC[tr.F(i)]++;
ll tot=0;
for(int i=0;i<N;i++)if(tr.F(i)==i)tot+=VC[tr.P[i]]*(VC[tr.P[i]]-1);
// cout<<tot<<'\n';
for(int i=0;i<N;i++)if(IS.test(i)==0)tot+=V[i].size();
cout<<tot;
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
376 KB |
Output is correct |
2 |
Correct |
2 ms |
376 KB |
Output is correct |
3 |
Correct |
2 ms |
436 KB |
Output is correct |
4 |
Incorrect |
2 ms |
488 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
6 ms |
1204 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
68 ms |
2008 KB |
Output is correct |
2 |
Incorrect |
173 ms |
12264 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |