#include<iostream>
#include<vector>
#define min(x,y)(x>y?y:x)
#define max(x,y)(x>y?x:y)
using namespace std;
int main()
{
int t,n,m,x,y;
cin>>t;
while(t--)
{int check=0,count=0;
vector<int>b(100004),a(100004); // a is for storing parent while b for storing no of connected node to parent
cin>>n>>m;
count=n; //count is variable for storing no of total nodes.
if(m==0)cout<<n<<endl;
else
{
for(int k=0;k<m;k++)
{
cin>>x>>y;
if(a[x+1]==0&&a[y+1]==0)
{
a[x+1]=min(x+1,y+1);a[y+1]=min(x+1,y+1);
b[min(x+1,y+1)]++;
}
else if(a[x+1]!=0&&a[y+1]!=0&&a[y+1]!=a[x+1])
{
b[a[x+1]]=b[a[x+1]]+b[a[y+1]]+1;
b[a[y+1]]=0;
a[y+1]=a[a[x+1]];
}
else if((a[x+1]!=a[y+1])&&(a[x+1]!=0||a[y+1]!=0))
{if(a[x+1]>0&&a[y+1]==0)
{
a[y+1]=a[a[x+1]];
b[a[a[x+1]]]++;
}
else
{a[x+1]=a[a[y+1]];b[a[a[y+1]]]++;
}
}
}
for(int i=1;i<=n;i++)count-=b[i];
cout<<count<<endl;
}
}
return 0;
}
I don't know where it's fail plz some one suggest how to solve it as i have used all the concept of no of different trees in forest for this i have taken two vector
a for storing parent node and b for stroing no of connected node to parent one.
