public static long Solve(int cityCount, List <Edge> edges)
{
edges.Sort((e1, e2) => e1.Cost.CompareTo(e2.Cost));
var citySets = new DisjointSets(cityCount);
long totalEdgeCost = 0;
for (int e = 0; e < edges.Count; ++e)
{
if (!citySets.AreInSameSet(edges[e].SourceCity, edges[e].DestinationCity))
{
citySets.UnionSets(edges[e].SourceCity, edges[e].DestinationCity);
totalEdgeCost += edges[e].Cost;
}
}
return(totalEdgeCost);
}
public void AreInSameSet()
{
var disjointSets = new DisjointSets(10);
for (int i = 0; i < 10; ++i)
{
for (int j = 0; j < 10; ++j)
{
if (i != j)
{
Assert.IsFalse(disjointSets.AreInSameSet(i, j));
}
else
{
Assert.IsTrue(disjointSets.AreInSameSet(i, j));
}
}
}
disjointSets.UnionSets(0, 3);
Assert.IsTrue(disjointSets.AreInSameSet(0, 3));
Assert.IsFalse(disjointSets.AreInSameSet(0, 4));
disjointSets.UnionSets(1, 4);
Assert.IsTrue(disjointSets.AreInSameSet(0, 3));
Assert.IsFalse(disjointSets.AreInSameSet(0, 4));
Assert.IsTrue(disjointSets.AreInSameSet(1, 4));
Assert.IsTrue(disjointSets.AreInSameSet(4, 1));
disjointSets.UnionSets(3, 1);
Assert.IsTrue(disjointSets.AreInSameSet(0, 4));
Assert.IsTrue(disjointSets.AreInSameSet(1, 3));
Assert.IsTrue(disjointSets.AreInSameSet(5, 5));
Assert.IsFalse(disjointSets.AreInSameSet(1, 5));
disjointSets.UnionSets(2, 5);
disjointSets.UnionSets(4, 2);
disjointSets.UnionSets(6, 7);
disjointSets.UnionSets(7, 9);
disjointSets.UnionSets(9, 0);
disjointSets.UnionSets(2, 6);
for (int i = 0; i < 10; ++i)
{
for (int j = 0; j < 10; ++j)
{
if (i != j)
{
if (i != 8 && j != 8)
{
Assert.IsTrue(disjointSets.AreInSameSet(i, j));
}
else
{
Assert.IsFalse(disjointSets.AreInSameSet(i, j));
}
}
else
{
Assert.IsTrue(disjointSets.AreInSameSet(i, j));
}
}
}
}
