fig closed knight' tour and getting stuck in the middle of the board this heuristic is not perfect and some backtracking is still required to find the solution neverthelesswithout this heuristic there would be no hope in solving the problem in reasonable amount of time for board in factthe solution can' be found in reasonable amount of time with simple depth first searchunless you get lucky and search in the correct direction at each step with the heuristic and hill climbing appliedthe solution can be found in just few seconds the -queens problem to solve the -queens problemn queens must be placed on an xn chess board so that no two queens are in the same columnrowor diagonal solving this using depth first search would not work the search space is too large and you would simply have to get very lucky to find solution using brute force the -queens problem does have the unique feature that when queen is placed on the boardall other locations in the rowcolumnor the diagonals it was placed in are no longer possible candidates for future moves removing these possible moves from the list of available locations is called forward checking this forward checking decreases the size of the search space at each step the choice of the next row to place queen is another unique feature of the -queens problem the solution won' be easier to find if random row is picked or this copy belongs to 'acha