//********************************************************************
public void heapifydown()
{
int li = data.Count - 1; //last index (after removal)
int pi = 0; // parent index. start at front of pq
while (true)
{
int ci = pi * 2 + 1; // left child index of parent
if (ci > li)
{
break; // no children so done
}
int rc = ci + 1; // right child
// if there is a right child , and it is smaller than left child, use the rc instead
if (rc <= li && data[rc].cost.CompareTo(data[ci].cost) < 0)
{
ci = rc;
}
// If parent is smaller than (or equal to) smallest child so done
if (data[pi].cost.CompareTo(data[ci].cost) <= 0)
{
break;
}
// Else swap parent and child
puzzel tmp = data[pi]; data[pi] = data[ci]; data[ci] = tmp;
pi = ci;
}
}
//********************************************************************
public puzzel Dequeue()
{
// assumes pq is not empty; up to calling code
int li = data.Count - 1; // last index (before removal)
puzzel frontItem = data[0]; // fetch the front
data[0] = data[li]; // last item be the root
data.RemoveAt(li);
heapifydown();
return(frontItem);
}
//**************************************************
public void Get_Path(puzzel goal)
{
// Get Path
puzzel p = goal.parent;
while (p.parent != null)
{
path.Add(p);
p = p.parent;
}
// Add Start Board
path.Add(p);
// call Display path
display_path();
}
//**********************************************
public Boolean check_if_child_in_closed(puzzel c)
{
bool check = false;
if (map_closed.ContainsKey(c.key))
{
puzzel _key = map_closed[c.key];
if (_key.cost < c.cost)
{
open_list.Enqueue(_key); map_open.Add(_key.key, _key);
}
check = true;
}
return(check);
}
//*******************************************************
public void A_Star_Algorithm(puzzel start)
{
map_open.Add(start.key, start);
open_list.Enqueue(start);
while (!open_list.is_empty())
{
puzzel current = new puzzel(open_list.Dequeue(), 0);
if (!check_if_child_in_closed(current))
{
map_closed.Add(current.key, current);
closed_list.Add(current);
// generate child from current
generate_child(current);
}
}
}
//*******************************************************************
//child constructor
public puzzel(puzzel p)
{
this.N = p.N;
this.puzzel2d = new int[N, N];
for (int i = 0; i < this.N; i++)
{
for (int j = 0; j < this.N; j++)
{
this.puzzel2d[i, j] = p.puzzel2d[i, j];
}
}
this.blank_index_i = p.blank_index_i;
this.blank_index_j = p.blank_index_j;
this.num_of_level = p.num_of_level + 1;
this.parent = p.parent;
}
//********************************************************************
public void heapifyup()
{
int ci = data.Count - 1; // child index; start at end
while (ci > 0)
{
int pi = (ci - 1) / 2; // parent index
// If child item is larger than (or equal) parent so we're done
if (data[ci].cost.CompareTo(data[pi].cost) >= 0)
{
break;
}
// Else swap parent & child
puzzel tmp = data[ci]; data[ci] = data[pi]; data[pi] = tmp;
ci = pi;
}
}
//*******************************************************************
//Equal constructor
public puzzel(puzzel p, int _default)
{
this.N = p.N;
this.puzzel2d = new int[N, N];
for (int i = 0; i < this.N; i++)
{
for (int j = 0; j < this.N; j++)
{
this.puzzel2d[i, j] = p.puzzel2d[i, j];
}
}
this.blank_index_i = p.blank_index_i;
this.blank_index_j = p.blank_index_j;
this.num_of_level = p.num_of_level;
this.hamming_val = p.hamming_val;
this.manhattan_val = p.manhattan_val;
this.cost = p.cost;
this.parent = p;
this.key = p.key;
}
//***************************************************************
//initial constructor
public puzzel(int size, int[,] puzzel_array, int blank_tile_i, int blank_tile_j)
{
this.N = size;
this.puzzel2d = new int[N, N];
for (int i = 0; i < this.N; i++)
{
for (int j = 0; j < this.N; j++)
{
this.puzzel2d[i, j] = puzzel_array[i, j];
this.key += puzzel_array[i, j];
}
}
this.direction = "Start";
this.blank_index_i = blank_tile_i;
this.blank_index_j = blank_tile_j;
this.num_of_level = 0;
this.hamming();
this.manhattan();
this.parent = null;
}
//*******************************************************
public void generate_child(puzzel p)
{
// check L||R||U||D
if (p.check_left())
{
puzzel c = new puzzel(p);
c.move_left();
c.manhattan();
c.calc_min_cost_using_manhattan();
if (c.is_goal_M())
{
c.direction = "Goal";
// Add Goal Board
path.Add(c);
Get_Path(c);
}
c.direction = "Left";
//check if child in open list or not
Boolean boo2;
boo2 = check_if_child_in_open(c);
if (boo2 == false)
{
open_list.Enqueue(c); map_open.Add(c.key, c);
}
}
if (p.check_right())
{
puzzel c = new puzzel(p);
c.move_right();
c.manhattan();
c.calc_min_cost_using_manhattan();
if (c.is_goal_M())
{
c.direction = "Goal";
// Add Goal Board
path.Add(c);
Get_Path(c);
}
c.direction = "Right";
//check if child in open list or not
Boolean boo2;
boo2 = check_if_child_in_open(c);
if (boo2 == false)
{
open_list.Enqueue(c); map_open.Add(c.key, c);
}
}
if (p.check_up())
{
puzzel c = new puzzel(p);
c.move_up();
c.manhattan();
c.calc_min_cost_using_manhattan();
if (c.is_goal_M())
{
c.direction = "Goal";
// Add Goal Board
path.Add(c);
Get_Path(c);
}
c.direction = "Up";
//check if child in open list or not
Boolean boo2;
boo2 = check_if_child_in_open(c);
if (boo2 == false)
{
open_list.Enqueue(c); map_open.Add(c.key, c);
}
}
if (p.check_down())
{
puzzel c = new puzzel(p);
c.move_down();
c.manhattan();
c.calc_min_cost_using_manhattan();
if (c.is_goal_M())
{
c.direction = "Goal";
// Add Goal Board
path.Add(c);
Get_Path(c);
}
c.direction = "Down";
//check if child in open list or not
Boolean boo2;
boo2 = check_if_child_in_open(c);
if (boo2 == false)
{
open_list.Enqueue(c); map_open.Add(c.key, c);
}
}
}
//**********************************************
public Boolean check_if_child_in_open(puzzel c)
{
bool check = map_open.ContainsKey(c.key);
return(check);
}
static void Main(string[] args)
{
// Read Board From File
FileStream fs = new FileStream("8 Puzzle (1).txt", FileMode.Open);
StreamReader sr = new StreamReader(fs);
while (sr.Peek() != -1)
{
String s = sr.ReadLine();
String[] fields;
fields = s.Split(' ');
int N;
N = int.Parse(fields[0]);
int val;
int[] puzzel1d = new int[N * N];
int[,] puzzel2d = new int[N, N];
int counter = 0;
for (int i = 0; i < N; i++)
{
s = sr.ReadLine();
fields = s.Split(' ');
for (int j = 0; j < N; j++)
{
val = int.Parse(fields[j]);
if (val == 0)
{
blank_i = i; blank_j = j;
}
puzzel2d[i, j] = val;
puzzel1d[counter] = val;
counter++;
}
}
//*****************************************************
char ch;
Console.WriteLine(" - Press [1] To Using A_Star With Hamming .");
Console.WriteLine(" - Press [2] To Using A_Star With Manhattan .");
Console.Write(" - Enter Your Choice : ");
ch = char.Parse(Console.ReadLine());
switch (ch)
{
//-----------------------------------------------------------------------------------
case '1':
{
// Check If Board Is Solvable Or Not
if (check_solvable(puzzel1d, N, blank_i))
{
Console.WriteLine();
Console.WriteLine(" - The Given Board Is < Solvable >");
Console.WriteLine(" __________________________ ");
Console.WriteLine();
puzzel start = new puzzel(N, puzzel2d, blank_i, blank_j);
A_Star_Using_Hamming A = new A_Star_Using_Hamming();
A.A_Star_Algorithm(start);
A.display_path();
}
else
{
Console.WriteLine("No Feasible Solution For The Given Board ");
}
}
break;
//-----------------------------------------------------------------------------------
case '2':
{
// Check If Board Is Solvable Or Not
if (check_solvable(puzzel1d, N, blank_i))
{
Console.WriteLine();
Console.WriteLine(" - The Given Board Is < Solvable >");
Console.WriteLine(" __________________________ ");
Console.WriteLine();
puzzel start = new puzzel(N, puzzel2d, blank_i, blank_j);
A_Star_Using_Manhattan A = new A_Star_Using_Manhattan();
A.A_Star_Algorithm(start);
}
else
{
Console.WriteLine(" - No Feasible Solution For The Given Board ");
}
}
break;
//-----------------------------------------------------------------------------------
default:
break;
//-----------------------------------------------------------------------------------
}
}
}
//********************************************************************
public void Enqueue(puzzel item)
{
data.Add(item);
heapifyup();
}