Question

 Random-restart hill climbing for the 8-puzzle with h2 as the heuristic function. Implement  preferably in C/C++ if not in Java or Python. 

Answer 1

public static bool HillClimbingRandomRestart(int[,] _state)
{
int[,] _current = _state;
int hMax = Problem.GetHeuristic(_state);
int Counter = 0;
int _h = hMax;
int[,] _best = _current;
int[,] _next = _current;
while (Counter < 100000)
{
Counter++;
if (isGoal(_current))
return true;
foreach (Move suit in Enum.GetValues(typeof(Move)))
{
_next = Problem.MoveEmptyTile(_current, suit);
if (_next == null)
continue;
_h = Problem.GetHeuristic(_next);
if (_h < hMax)
{
hMax = _h;
_best = _next;
}
}
if (_current == _best)
{
Random rnd = new Random();
int[,] _nextRandom = Problem.MoveEmptyTile(_current, (Move)rnd.Next(4));
while(_nextRandom==null)
_nextRandom = Problem.MoveEmptyTile(_current, (Move)rnd.Next(4));
_current = _nextRandom;
}
else
_current = _best;
hMax = Problem.GetHeuristic(_current);
}
return false;
}

// You can make changes in this code .