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());
            }