#include "bits/stdc++.h"
using namespace std;
const int MAX=1e6+99;
vector<int> vec[MAX];
pii E[MAX];
int linear[4],destruct[4],deg[4][MAX],OtherEnd[4][MAX];
int N,M,cnt,CycleSize,Quad,a,b,lol,size_[MAX];
void Init(int N_)
{
M=0;
N=N_;
cnt=0;
Quad=0;
CycleSize=0;
for(int A=0;A<N;A++)
{
size_[A]=1;
deg[0][A]=0;
OtherEnd[0][A]=A;
vec[A].clear();
}
return ;
}
void Add(int X,int Y)
{
for(int A=0;A<4;A++)
{
if(!linear[A] or destruct[A]==X or destruct[A]==Y)
continue;
deg[A][X]++;
deg[A][Y]++;
if(deg[A][X]==3 or deg[A][Y]==3 or OtherEnd[A][X]==Y)
{
linear[A]=0;
continue;
}
a=OtherEnd[A][X];
b=OtherEnd[A][Y];
OtherEnd[A][X]=-1;
OtherEnd[A][Y]=-1;
OtherEnd[A][a]=b;
OtherEnd[A][b]=a;
}
return ;
}
void Split(int X)
{
Quad=1;
destruct[0]=X;
destruct[1]=vec[X][0];
destruct[2]=vec[X][1];
destruct[3]=vec[X][2];
for(int A=0;A<4;A++)
{
linear[A]=1;
for(int B=0;B<N;B++)
{
deg[A][B]=0;
OtherEnd[A][B]=B;
}
}
for(int A=0;A<M;A++)
Add(E[A].first,E[A].second);
return ;
}
void Link(int X,int Y)
{
if(cnt>2)
return ;
if(Quad==0)
{
vec[X].push_back(Y);
vec[Y].push_back(X);
deg[0][X]++;
deg[0][Y]++;
if(deg[0][X]==3)
{
Split(X);
return ;
}
if(deg[0][Y]==3)
{
Split(Y);
return ;
}
if(OtherEnd[0][X]!=Y)
{
lol=size_[a];
size_[a]=lol+size_[b];
size_[b]=lol+size_[b];
a=OtherEnd[0][X];
b=OtherEnd[0][Y];
OtherEnd[0][X]=-1;
OtherEnd[0][Y]=-1;
OtherEnd[0][a]=b;
OtherEnd[0][b]=a;
return ;
}
cnt++;
if(cnt==1)
CycleSize=size_[Y];
}
else
Add(X,Y);
return ;
}
int CountCritical()
{
if(!Quad)
{
if(cnt>1)
return 0;
else if(CycleSize)
return CycleSize;
else
return N;
}
else
return (linear[0]+linear[1]+linear[2]+linear[3]);
}
Compilation message
rings.cpp:8:1: error: 'pii' does not name a type
pii E[MAX];
^~~
rings.cpp: In function 'void Split(int)':
rings.cpp:71:7: error: 'E' was not declared in this scope
Add(E[A].first,E[A].second);
^
