// put an element of type pair in priority queue
public void Insert(Node_info value)
{
EnsureHeapCapacity();
heap.Add(value);
heapify_up(size);
size++;
}
private void heapify_down(int idx)
{
while (get_left_child_index(idx) < size)
{
int left_child_idx = get_left_child_index(idx);
int min_idx = idx;
if (heap[min_idx].CompareTo(heap[left_child_idx]) == 1)
{
min_idx = left_child_idx;
}
int right_child_idx = get_right_child_index(idx);
if (right_child_idx < size && heap[min_idx].CompareTo(heap[right_child_idx]) == 1)
{
min_idx = right_child_idx;
}
if (min_idx != idx)
{
Node_info temp = heap[idx];
heap[idx] = heap[min_idx];
heap[min_idx] = temp;
}
else
{
return;
}
idx = min_idx;
}
}
// compares 2 pairs return 0 if both are equal 1 if PHANTOM object is greater -1 if parameter object is greater
public int CompareTo(Node_info P)
{
if (Math.Abs(item3 - P.item3) < double.Epsilon)
{
return(0);
}
else if (item3 - P.item3 < 0)
{
return(-1);
}
return(1);
}
public static void shortest_path(int x, int y)
{
int width = ImageOperations.GetWidth(MainForm.ImageMatrix);
int height = ImageOperations.GetHeight(MainForm.ImageMatrix);
Console.WriteLine(x + " " + y);
int starting_node = generate_id(x, y, ImageOperations.GetWidth(MainForm.ImageMatrix));
int[] parent1 = new int[width * height + 5];
bool[] vis = new bool[width * height + 5];
double[] values = new double[width * height + 5];
for (int i = 0; i < width * height + 2; ++i)
{
values[i] = double.MaxValue;
}
PriorityQueue q = new PriorityQueue();
Node_info n = new Node_info(1258, -1, 0);
q.Insert(n);
while (!q.is_empty())
{
n = q.poll();
double val = Convert.ToDouble(n.get_item3());
int cur = Convert.ToInt32(n.get_item1());
int par = Convert.ToInt32(n.get_item2());
if (vis[cur])
{
continue;
}
vis[cur] = true;
values[cur] = val;
parent1[cur] = par;
for (int i = 0; i < adjlist[cur].Count; i++)
{
double weight = adjlist[cur][i].Item2;
weight += val;
Node_info n1 = new Node_info(adjlist[cur][i].Item1, cur, weight);
q.Insert(n1);
}
}
List <int> Par = new List <int>();
int nn = 4334;
while (parent1[nn] != -1)
{
Console.WriteLine(parent1[nn]);
Par.Add(parent1[nn]);
nn = parent1[nn];
}
WriteFilePath(Par, Par.Count, width, 1258, 4334);
WriteFileOutput(adjlist, height);
}
private void heapify_up(int idx)
{
int parent = get_parent_index(idx);
while (idx > 0 && heap[idx].CompareTo(heap[parent]) == -1)
{
Node_info temp = heap[idx];
heap[idx] = heap[parent];
heap[parent] = temp;
idx = parent;
parent = get_parent_index(idx);
}
}
// return and remove the minimum pair in Priority queue
public Node_info poll()
{
if (size == 0)
{
throw new IndexOutOfRangeException();
}
Node_info temp = heap[0];
heap[0] = heap[size - 1];
heap[size - 1] = temp;
heap.RemoveAt(size - 1);
size--;
heapify_down(0);
return(temp);
}