def test_borders_constraint(self):
# Create maze
n_rows = 3
n_cols = 3
start = '0,1n'
end = '0,3w'
maze = Maze(n_rows, n_cols, start, end, ['1,1w', '2,1n'])
maze._apply_valid_move_constraint() # Apply constraint to populate csp variables
maze._set_start_and_end() # Start and end locations should not be considered as borders
# Grab border variables
borders = {get_label(i, 0, 'w') for i in range(n_rows)} # West border
borders.update({get_label(i, n_cols, 'w') for i in range(n_rows)}) # East border
borders.update({get_label(0, j, 'n') for j in range(n_cols)}) # North border
borders.update({get_label(n_rows, j, 'n') for j in range(n_cols)}) # South border
borders.remove(start)
borders.remove(end)
# Check to see that border appears as a variable in maze.csp
for border in borders:
self.assertTrue(border in maze.csp.variables)
# Fix borders
maze._set_borders()
# Check to see that borders are fixed; they would no longer appear as variables
for border in borders:
self.assertFalse(border in maze.csp.variables)
# Verify that borders are fixed to 0.
# If borders were fixed to 1, this good_path_solution would cause the valid_move_constraint to fail.
good_path_solution = {'0,2w': 1}
fill_with_zeros(good_path_solution, n_rows, n_cols, [start, end])
self.assertTrue(maze.csp.check(good_path_solution))
def fill_with_zeros(solution_dict, n_rows, n_cols, ignore_list=None):
keys = set(itertools.chain(solution_dict.keys(), ignore_list or []))
# Setting west direction to zero
for i in range(n_rows):
for j in range(n_cols + 1):
west = get_label(i, j, 'w')
if west not in keys:
solution_dict[west] = 0
# Setting north direction to zero
for i in range(n_rows + 1):
for j in range(n_cols):
north = get_label(i, j, 'n')
if north not in keys:
solution_dict[north] = 0