public void MakeSet(Subset[] subsets)
{
for (int i = 1; i < subsets.Length; i++)
{
subsets[i] = new Subset();
subsets[i].Parent = i;
subsets[i].Rank = 0;
}
}
public static int getMinimumCostToConstruct(int n, List <List <int> > edges, List <List <int> > newEdges)
{
if (n == 0)
{
return(0);
}
HashSet <int> hs = new HashSet <int>();
var edgeList = new List <(int, int, int)>();
DisJointSets djs = new DisJointSets();
Subset[] subsets = new Subset[n + 1];
int totalCost = 0;
//get all the edges from the adjecency list
foreach (var item in edges)
{
edgeList.Add((item[0], item[1], 0));
edgeList.Add((item[1], item[0], 0));
hs.Add(item[0]);
hs.Add(item[1]);
}
foreach (var newIitem in newEdges)
{
edgeList.Add((newIitem[0], newIitem[1], newIitem[2]));
edgeList.Add((newIitem[1], newIitem[0], newIitem[2]));
hs.Add(newIitem[0]);
hs.Add(newIitem[1]);
}
//All nodes are not connected by the available edges;
//if (hs.Count != n) return -1;
edgeList.Sort((a, b) => a.Item3 - b.Item3);
djs.MakeSet(subsets);
foreach (var edge in edgeList)
{
int x = djs.FindSet(subsets, edge.Item1);
int y = djs.FindSet(subsets, edge.Item2);
//exclude the edge if the reperesenting vertex is equal
//it means there is a cycle so do not need to include in spanning tree
if (x != y)
{
totalCost += edge.Item3;
djs.Union(subsets, x, y);
}
}
return(totalCost);
}