This program will solve the problem of placing 8 queens on a chess board such that none of them attack each other. There will also be a boulder placed in the board which blocks the queens' attack and occupies a place on the board.
It makes use of hill-climbing with random restart algorithm:
Defining neighborhood:
- Goal state: queens are not attacking each other and are placed in valid positions (multiple queens are not in the same position or in the same position as the boulder)
- Neighbor state: from the current state, move ONE queen to a valid position along its column
- Heuristic value: the number of queens being attacked (the lower the value, the better the state)
Algorithm:
- Move each the queens from the right-most respectively to the position with the lowest heuristic value
- Stop if the goal state is reached
- If the goal state is not reached after all queens are moved, restart by placing each queen on a column randomly