public long Calculate(bool[][] graph)
{
var size = graph.Length;
var bitGraph = new BitSet2048[size];
var init = Enumerable.Range(0, size)
.Select(x => true)
.ToArray();
for (var index = 0; index < size; index++)
{
bitGraph[index] = new BitSet2048(graph[index]);
}
return(Enumerable.Range(0, size)
.Select(x => GetDistanceSquareSum(bitGraph, init, x))
.Sum());
}
private static long GetDistanceSquareSum(BitSet2048[] graph, bool[] init, int startIndex)
{
var size = graph.Length;
var queue = new Queue <int>();
var distance = new long?[size];
var notUsed = new BitSet2048(init);
var work = BitSet2048.CreateClear();
distance[startIndex] = 0;
queue.Enqueue(startIndex);
notUsed[startIndex] = false;
while (queue.Any())
{
var currentIndex = queue.Dequeue();
var currentDistance = distance[currentIndex];
var currentRow = graph[currentIndex];
for (var index = 0; index < work.Clusters.Length; index++)
{
work.Clusters[index] = notUsed.Clusters[index] & currentRow.Clusters[index];
}
var items = work.GetItems();
foreach (var index in items)
{
distance[index] = currentDistance + 1;
notUsed[index] = false;
queue.Enqueue(index);
}
}
return(distance
.Select(x => x ?? size)
.Select(x => x * x)
.Sum());
}
