def BFS(start, goal):
notVis = []
pathLen = 0
nodeCount = 0
goalHash = Common.stateToHash(goal)
#children = []
n = stateToNode(start, None)
if(Common.stateToHash(n.curState) == goalHash):
return [True, 0]
vis = []
vis.append(Common.stateToHash(n.curState))
while True:
children = []
if(notVis.__len__() != 0):
n = notVis.pop(0)
succ = generateSuccesorStates(n.curState)
if succ.__len__() == 0:
break
for x in succ:
child = stateToNode(x, n)
children.append(child)
for i in children:
curHash = Common.stateToHash(i.curState)
nodeCount = nodeCount+1
if(curHash not in vis):
if(curHash == goalHash):
#path = getPath(i, (pathLen+1))
path = getPath(i)
for j in reversed(path):
displayBoard(j)
print""
print "Number of Nodes Expanded: ", nodeCount
stateStrings = Common.pathString(path)
return stateStrings
notVis.append(i)
vis.append(curHash)
pathLen = pathLen + 1
print "No path Found"
return []
def DFS(start, goal):
#convert goal state to hash string
g = Common.stateToHash(goal)
#make the list of visted an empty list
vis = []
d = 'n'
res = dfs_rec(start, d, vis, g)
if(res):
print("found goal state")
print(path)
else:
print("did not find goal state")
def dfs_rec(oldCur, d, oldVis, goal):
cur = copy.deepcopy(oldCur)
vis = copy.deepcopy(oldVis)
#change current state in the direction of d
cur = Common.mod(cur, d)
#if our current state could not be reached (ie trying to swap with outside of the matrix) don't check this branch
if(cur == None):
return False
hashstate = Common.stateToHash(cur)
#if we are the goal state return our current state and true
if(hashstate == goal):
path.insert(0, cur)
return True
#if this is a visited state stop
if(hashstate in vis):
return False
#if not visited then add it to the visited list
else:
vis.append(hashstate)
#check right move
ret = dfs_rec(cur, 'l', vis, goal)
if(ret == True):
path.insert(0, cur)
return True
#check left move
ret = dfs_rec(cur, 'r', vis, goal)
if(ret == True):
path.insert(0, cur)
return True
#check up move
ret = dfs_rec(cur, 'u', vis, goal)
if(ret == True):
path.insert(0, cur)
return True
#check left move
ret = dfs_rec(cur, 'd', vis, goal)
if(ret == True):
path.insert(0, cur)
return True
else:
return False
