HackerEarth Maximum Spanning Tree problem solution

In this HackerEarth Maximum Spanning Tree problem solution You are given a weighted graph with N vertices and M edges. Find the total weight of its maximum spanning tree.

HackerEarth Maximum Spanning Tree problem solution.

#include<bits/stdc++.h>

using namespace std;

int tests;
int n,m;
int a[1<<20],b[1<<20],c[1<<20];
vector<pair<int, int> > v;
int w[1<<20];
int ans;

int get(int x)
{
  if (x==w[x])
    return x;
  return w[x]=get(w[x]);
}

void merge(int a,int b)
{
  w[a]=b;
}

int main(){
ios_base::sync_with_stdio(0);

cin>>tests;
for (;tests;--tests)
{
  cin>>n>>m;
  v.clear();
  for (int i=1;i<=m;i++)
  {
    cin>>a[i]>>b[i]>>c[i];
    v.push_back(make_pair(c[i],i));
  }
  sort(v.begin(),v.end());
  reverse(v.begin(),v.end());
  for (int i=1;i<=n;i++)
    w[i]=i;
    
  ans=0;
  
  for (int i=0;i<v.size();i++)
  {
    int id=v[i].second;
    int q,w;
    q=a[id];
    w=b[id];
    q=get(q);
    w=get(w);
    if (q!=w)
    {
      ans+=c[id];
      merge(q,w);
    }
  }
  cout<<ans<<endl;
}

return 0;}