Graph Theory NO.1 HDU_1213_How Many Tables_并查集

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
int num[10000];
int father[10000];
int Init(int n)//初始化
{
for(int i=1;i<=n;i++)
{
father[i]=i;
num[i]=1;
}
return 0;
}
int Find(int x)//查找根
{
if(father[x]!=x)
{
father[x]=Find(father[x]);
}
return father[x];
}
int Union(int a,int b)//并上去
{
if(a==b)return 0;
if(num[a]<num[b])
{
father[a]=b;
num[b]+=num[a];
}
else
{
father[b]=a;
num[a]+=num[b];
}
return 0;
}
int main()
{
int t,n,m;
while(~scanf("%d",&t))
{
while(t--)
{
int a,b;
scanf("%d%d",&n,&m);
memset(father,0,sizeof(father));
memset(num,0,sizeof(num));
Init(n);//初始化；
for(int i=0;i<m;i++)
{
scanf("%d%d",&a,&b);
Union(Find(a),Find(b));//查和并；
}
int count=0;
for(int i=1;i<=
4000
n;i++)
{
if(father[i]==i)
{
count++;
}
printf("%d\n",father[i]);
}
printf("%d\n",count);
}
}
return 0;
}