def ida_search_function(node,g,threshold,method):
global md_step
global hu_step
if method == "MD":
f_value = g + heuristic.manhattan_distance_node(node)
md_step += 1
else:
f_value = g + heuristic.hungarian_method(node)
hu_step += 1
if (f_value >threshold):
return f_value
if (board.check_goal(node)):
print("IDA* Goal achieved:")
if method == "MD":
print("Steps: {}" .format(md_step))
else:
print("Steps: {}" .format(hu_step))
board.draw_board(node)
return -1
min = float("inf")
frontier = board.gen_frontier(node)
for i in range(1, len(frontier), 2):
tempvalue = ida_search_function(frontier[i], g+1, threshold, method)
if (tempvalue == -1):
return -1
if (tempvalue < min):
min = tempvalue
return min
def rbfs_search_function(f_node, f_limit, depth, method):
global rbfs_md_step
global rbfs_hu_step
if board.check_goal(f_node.n):
print("RBFS Goal Achieved:")
if method == "MD":
print("Steps: {}".format(rbfs_md_step))
else:
print("Steps: {}".format(rbfs_hu_step))
board.draw_board(f_node.n)
return "SUCCESS", f_node.f
frontier = board.gen_frontier(f_node.n)
if len(frontier) == 0:
return "FAILURE", infinity
successors = []
for i in range(1, len(frontier), 2):
if method == "MD":
rbfs_md_step += 1
successors.append(F_node(max((depth + heuristic.manhattan_distance_node(frontier[i])), f_node.f), frontier[i], depth))
else:
rbfs_hu_step += 1
successors.append(F_node(max((depth + heuristic.hungarian_method(frontier[i])), f_node.f), frontier[i], depth))
while True:
successors.sort()
best_node = successors[0]
if best_node.f > f_limit:
return "FAILURE", best_node.f
if len(successors) == 1:
alternative = successors[0]
else:
alternative = successors[1]
result, best_node.f = rbfs_search_function(best_node, min(f_limit, alternative.f),depth+1,method)
if result != "FAILURE":
return result, best_node.f
def ida_run(evaluation_board,method):
if method == "MD":
ida_threshold = heuristic.manhattan_distance_node(evaluation_board)
else:
ida_threshold = heuristic.hungarian_method(evaluation_board)
while True:
search_result = ida_search_function(evaluation_board,0,ida_threshold,method)
if (search_result == -1):
return "GOAL"
ida_threshold = search_result