Cod sursă (job #720133)

#include<bits/stdc++.h>
using namespace std;

typedef pair<int, int> iPair;

struct Graph
{
    int V, E;
    vector< pair<int, iPair> > edges;

    Graph(int V, int E)
    {
        this->V = V;
        this->E = E;
    }
  
 
    void addEdge(int u, int v, int w)
    {
        edges.push_back({w, {u, v}});
    }
  
    int kruskalMST();
};
  

struct DisjointSets
{
    int *parent, *rnk;
    int n;
  
  
    DisjointSets(int n)
    {
       
        this->n = n;
        parent = new int[n+1];
        rnk = new int[n+1];
        for (int i = 0; i <= n; i++)
        {
            rnk[i] = 0;
  
            parent[i] = i;
        }
    }
    int find(int u)
    {

        if (u != parent[u])
            parent[u] = find(parent[u]);
        return parent[u];
    }

    void merge(int x, int y)
    {
        x = find(x), y = find(y);
  
    
        if (rnk[x] > rnk[y])
            parent[y] = x;
        else
            parent[x] = y;
  
        if (rnk[x] == rnk[y])
            rnk[y]++;
    }
};
  

int Graph::kruskalMST()
{
    int mst_wt = 0;
    sort(edges.begin(), edges.end());
    DisjointSets ds(V);

    vector< pair<int, iPair> >::iterator it;
    for (it=edges.begin(); it!=edges.end(); it++)
    {
        int u = it->second.first;
        int v = it->second.second;
  
        int set_u = ds.find(u);
        int set_v = ds.find(v);
        if (set_u != set_v)
        {

            mst_wt += it->first;

            ds.merge(set_u, set_v);
        }
    }
  
    return mst_wt;
}
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	afreopen("zapada.in","r",stdin);
	freopen("zapada.out","w",stdout);
    int V, E,M,K,x,y,weight;
    cin>>V;
    cin>>M;
    cin>>K;
    E=M+K;
    
    Graph g(V, E);
    for(int i=0;i<M;i++){
    	cin>>x;
    	cin>>y;
    	cin>>weight;
    	g.addEdge(x,y,weight);
	}
    int mst_wt = g.kruskalMST();
    cout<< mst_wt<<endl;
    for(int i=0;i<K;i++){
    	cin>>x;
    	cin>>y;
    	cin>>weight;
    	g.addEdge(x,y,weight);
    	mst_wt = g.kruskalMST();
    	cout<< mst_wt<<endl;
	}
    return 0;
}