private IEnumerable<HeapNode> getValidMoves(string[] plan, HeapNode node, int[,] distances)
{
int left = node.Square - 1;
int right = node.Square + 1;
int up = node.Floor - 2;
int down = node.Floor + 2;
// left
if (left >= 0 && (plan[node.Floor][left] == '#' || plan[node.Floor][left] == 'F') && distances[node.Floor, node.Square] + 2 < distances[node.Floor, left])
{
distances[node.Floor, left] = distances[node.Floor, node.Square] + 2;
yield return new HeapNode(node.Floor, left);
}
// right
if (right < plan[node.Floor].Length && (plan[node.Floor][right] == '#' || plan[node.Floor][right] == 'F') && distances[node.Floor, node.Square] + 2 < distances[node.Floor, right])
{
distances[node.Floor, right] = distances[node.Floor, node.Square] + 2;
yield return new HeapNode(node.Floor, right);
}
// up
if (up < plan.Length && (plan[up][node.Square] == '#' || plan[up][node.Square] == 'F') && plan[up - 1][node.Square] == '|' && distances[up, node.Square] + 3 < distances[up, node.Square])
{
distances[up, node.Square] = distances[node.Floor, node.Square] + 3;
yield return new HeapNode(up, node.Square);
}
// down
if (down > 0 && (plan[down][node.Square] == '#' || plan[down][node.Square] == 'F') && plan[down - 1][node.Square] == '|' && distances[down, node.Square] + 1 < distances[down, node.Square])
{
distances[down, node.Square] = distances[node.Floor, node.Square] + 1;
yield return new HeapNode(down, node.Square);
}
}
public int wayTime(string[] plan)
{
int[] start = new int[2];
int[] end = new int[2];
for (int floor = 0; floor < plan.Length; floor += 2)
{
for (int square = 0; square < plan[floor].Length; square++)
{
if (plan[floor][square] == 'S')
{
start[Floor] = floor;
start[Square] = square;
}
if (plan[floor][square] == 'F')
{
end[Floor] = floor;
end[Square] = square;
}
}
}
int[,] distances = new int[plan.Length, plan[0].Length];
int minDistance = int.MaxValue;
HeapNode root = new HeapNode(start[Floor], start[Square]);
MinHeap heap = new MinHeap(root, distances);
while (heap.HasItems)
{
HeapNode node = heap.Top();
foreach (HeapNode move in getValidMoves(plan, node, distances))
{
if (plan[move.Floor][move.Square] == '#')
{
heap.Add(move);
}
else if (plan[move.Floor][move.Square] == 'F' && minDistance > distances[move.Floor, move.Square])
{
minDistance = distances[move.Floor, move.Square];
}
}
}
return minDistance;
}
public void Add(HeapNode n)
{
m_tail++;
m_data[m_tail] = n;
Bubble(m_tail);
}
public MinHeap(HeapNode root, int[,] distances)
{
m_data = new HeapNode[1000000];
m_data[0] = root;
m_tail = 0;
m_distances = distances;
}
