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| #include<bits/stdc++.h>
using namespace std;
const int MAX = 300005;
int id[MAX], nodes, edges, idx;
pair <int, pair<int, int> > p[MAX], output[MAX];
void initialize()
{
for(int i = 0; i < MAX; i++)
{
id[i] = i;
}
}
int root(int x)
{
while(id[x] != x)
{
id[x] = id[ id[x] ];
x = id[x];
}
return x;
}
void union1(int x, int y)
{
int p = root(x);
int q = root(y);
id[p] = id[q];
}
int kruskal(pair <int, pair<int, int> > p[])
{
idx = 0;
int x,y;
int cost, minimumcost = 0;
for(int i = 0; i < edges; i++)
{
/// selecting edges one by one in increasing order from the beginning.
x = p[i].second.first;
y = p[i].second.second;
cost = p[i].first;
/// check if the selected edge is creating a cycle or not
if(root(x) != root(y))
{
minimumcost += cost;
output[idx++] = make_pair(cost, make_pair(x,y));
union1(x,y);
}
}
return minimumcost;
}
int main()
{
// freopen("in.txt", "r", stdin);
int x,y;
int weight,cost,minimumcost,price;
initialize();
scanf("%d %d", &nodes, &edges);
//cout << nodes << " & "<<edges<<endl;
for(int i = 0; i < edges; i++)
{
cin >> x >> y >> weight;
p[i] = make_pair(weight, make_pair(x,y));
}
sort(p, p+edges);
// for(int i = 0; i < edges; i++){
// cout << p[i].second.first << " "<<p[i].second.second << " "<<p[i].first<<endl;
//}
minimumcost = kruskal(p);
cout << "MST :- ";
cout << minimumcost<<endl;
for(int i = 0; i < idx; i++){
cout << output[i].second.first << " "<<output[i].second.second << " "<< output[i].first << endl;
}
return 0;
}
|
