并查集的基本操作

#include<iostream>
typedef int T;
T const &Find(T const &element,T *father)
{
if(father[element]<0)
{
return element;
}
else
{
return father[element]=Find(father[element],father);
}
}

T const &Union(T const &element_a,T const &element_b,T *father)
{
if(father[element_a]<father[element_b])
{
father[element_a]+=father[element_b];
return father[element_b]=element_a;
}
else
{
father[element_b]+=father[element_a];
return father[element_a]=element_b;
}
}

int main()
{
using namespace std;
int N,M;
cin>>N>>M;
int *father=new int[N+1];
for(int i=0;i<=N;++i)
{
father[i]=-1;
}
for(int i=0;i<M;++i)
{
int n,data;
cin>>n>>data;
data=Find(data,father);
for(int j=1;j<n;++j)
{
int other_data;
cin>>other_data;
other_data=Find(other_data,father);
if(other_data!=data)
{
data=Union(other_data,data,father);
}
}
}
int max=1;
for(int i=1;i<=N;++i)
{
if(father[i]<0 && max<-father[i])
max=-father[i];
}
cout<<max<<endl;
delete[] father;
}