def evaluate(expression):
# trivial cases
if not expression:
return 0
operands = {
'+': (lambda x, y: x + y),
'-': (lambda x, y: x - y),
'*': (lambda x, y: x * y),
'/': (lambda x, y: x // y)
}
stack = Stack()
# convert the incoming string to an array
exp = expression.split(',')
# iterate through each exp
for e in exp:
if e in operands: # if operand, pop two numbers and calculate a b .
p1 = stack.pop()
p2 = stack.pop()
res = operands[e](p2, p1)
stack.push(res)
else: # else push the number onto stack
val = int(e)
stack.push(val)
final_res = stack.pop()
return final_res
class TestStack(unittest.TestCase):
def setUp(self):
self.stack = Stack()
def tearDown(self):
del self.stack
def test_push(self):
self.stack.push('A')
value = self.stack.get(0)
self.assertEqual(value, 'A')
def test_pop(self):
self.stack.push('A')
self.stack.push('B')
value = self.stack.pop()
self.assertEqual(value, 'B')
def shortest_equivalent_path(path):
stack = Stack()
# append '/' onto the stack
stack.push('/')
# split the path on the basis of '/'
path_names = path.split('/')
for name in path_names:
if (len(name) != 0 and name != '.'): # ignore '.' and ''
if (name == '..'): # pop from the stack
if (stack.top() == '/' or stack.top() == '..'): # if there's no dir push .. onto the stack
stack.push(name)
else:
dir_ = stack.pop()
else:
stack.push(name)
new_path = ''
val = stack.pop()
while (val != '/'):
new_path = val + '/' + new_path
val = stack.pop()
# if initial path starts with '/' then push that onto the new_path
if (path[0] == '/'):
return val + new_path[:-1]
return new_path[:-1]
class Processor(object):
def __init__(self):
'''Creates the lists'''
self.callahead = DoublyLinkedList()
self.waiting = DoublyLinkedList()
# self.waiting.debug_print()
# self.waiting.add('a')
# self.waiting.add('b')
# self.waiting.add('c')
# self.waiting.debug_print()
self.appetizers = Queue()
self.buzzers = Stack()
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.songs = CircularLinkedList()
self.songs.add('Song 1')
self.songs.add('Song 2')
self.songs.add('Song 3')
self.songs_iter = CircularLinkedListIterator(self.songs)
def run(self, f):
'''Processes the given file stream.'''
for index, line in enumerate(f):
line = line.rstrip()
print('{}:{}'.format(index, line))
parts = line.split(',')
# try:
func = getattr(self, '{}'.format(parts[0].lower()))
func(*parts[1:])
# except Exception as e:
# print('Error: {}'.format(e))
# split and handle the commands here
def debug(self, *args):
self.callahead.debug_print()
self.waiting.debug_print()
self.appetizers.debug_print()
self.buzzers.debug_print()
self.songs.debug_print()
def song(self, *args):
print(self.songs_iter.next())
def appetizer(self, *args):
try:
print("{} >>> {}".format(
self.appetizers.dequeue(),
', '.join([str(item)
for item in self.waiting.getLastThree()])))
except Exception as e:
print('Error:', e)
def appetizer_ready(self, *args):
self.appetizers.enqueue(args[0])
def seat(self, *args):
self.buzzers.push('Buzzer')
print(self.waiting.get(0))
self.waiting.delete(0)
def call(self, *args):
self.callahead.add(args[0])
def arrive(self, *args):
if (self.callahead.deleteByValue(args[0]) == True):
self.waiting.insert(self.getFiveIn(self.waiting.size), args[0])
else:
sws = self.waiting.size
self.waiting.insert(sws if sws >= 0 else 0, args[0])
self.buzzers.pop()
def leave(self, *args):
self.waiting.deleteByValue(args[0])
self.buzzers.push('Buzzer')
def getFiveIn(self, size):
return size - 4 if size - 4 >= 0 else 0
class Processor(object):
def __init__(self):
'''Creates the lists'''
self.callahead = DoublyLinkedList()
self.waiting = DoublyLinkedList()
self.appetizers = Queue()
self.buzzers = Stack()
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.songs = CircularLinkedList()
self.songs.add('Song 1')
self.songs.add('Song 2')
self.songs.add('Song 3')
self.songs_iter = CircularLinkedListIterator(self.songs)
def run(self, f):
'''Processes the given file stream.'''
for line_i, line in enumerate(f):
line = line.rstrip()
# split and handle the commands here
print('{}:{}'.format(line_i, line))
parts = line.split(',')
try:
func = getattr(self, 'cmd_{}'.format(parts[0].lower()))
func(*parts[1:])
except Exception as e:
print('Error: {}'.format(e))
def cmd_appetizer(self, *args):
wait = []
r = self.waiting._get_node(self.waiting.size - 1)
i = 0
try:
if self.waiting.size > 3:
i = self.waiting.size - 3
for x in range(self.waiting.size, i,-1):
wait.append(str(r.value))
r = r.prev
print('{} >>> {}'.format(self.appetizers.dequeue(), ', '.join(wait)))
except:
raise IndexError('The given index is not within the bounds of the current list.')
def cmd_appetizer_ready(self, *args):
self.appetizers.enqueue(args[0])
def cmd_call(self, *args):
self.callahead.add(args[0])
def cmd_arrive(self, *args):
if (self.callahead.check_value(args[0])):
if self.waiting.size > 5:
self.waiting.insert(self.waiting.size - 4, args[0])
index = self.callahead.check_index(args[0])
self.callahead.delete(index)
else:
self.waiting.insert(0, args[0])
index = self.callahead.check_index(args[0])
self.callahead.delete(index)
else:
self.waiting.add(args[0])
self.buzzers.pop()
def cmd_leave(self, *args):
self.buzzers.push('Buzzer')
index = self.waiting.check_index(args[0])
self.waiting.delete(index)
def cmd_seat(self, *args):
if self.waiting.size != 0:
self.buzzers.push('Buzzer')
next_party = self.waiting._get_node(0)
print(next_party.value)
self.waiting.delete(0)
else:
raise IndexError('The given index is not within the bounds of the current list.')
def cmd_debug(self, *args):
self.callahead.debug_print()
self.waiting.debug_print()
self.appetizers.debug_print()
self.buzzers.debug_print()
self.songs.debug_print()
def cmd_song(self, *args):
val = self.songs_iter.next()
print(val)
class Processor(object):
def __init__(self):
'''Creates the lists'''
self.callahead = DoublyLinkedList()
self.waiting = DoublyLinkedList()
self.appetizers = Queue()
self.buzzers = Stack()
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.songs = CircularLinkedList()
self.songs.add('Song 1')
self.songs.add('Song 2')
self.songs.add('Song 3')
self.songs_iter = CircularLinkedListIterator(self.songs)
def run(self, f):
'''Processes the given file stream.'''
self.songs.debug_print()
for line_i, line in enumerate(f):
line = line.rstrip()
comms = line.split(',')
print('%d:%s' % (line_i, line))
if comms[0] == 'SEAT':
print('SEAT >>>>', line)
elif comms[0] == 'APPETIZER':
wait_iter = DoublyLinkedListIterator(self.waiting)
while wait_iter.has_next():
wait_iter.next()
count = 0
person_array = []
try:
food = self.appetizers.dequeue()
except:
print('error')
while wait_iter.has_prev() and count < 3:
person_array.append(wait_iter.node.value)
count += 1
print('%s >>> %s' % (food, ', '.join(person_array)))
elif comms[0] == 'SONG':
self.songs_iter.next()
print(self.songs_iter.node.value)
elif comms[0] == 'LEAVE':
self.waiting.delete(comms[1])
elif comms[0] == 'DEBUG':
self.debug()
elif comms[0] == 'ARRIVE':
self.waiting.add(comms[1])
try:
self.callahead.delete(comms[1])
except ValueError('error'):
continue
elif comms[0] == 'CALL':
self.callahead.add(comms[1])
elif comms[0] == 'APPETIZER_READY':
self.appetizers.enqueue(comms[1])
else:
print("ERROR!!!!!", line)
# split and handle the commands here
def debug(self):
'''print all objects'''
self.callahead.debug_print()
self.waiting.debug_print()
self.appetizers.debug_print()
self.buzzers.debug_print()
self.songs.debug_print()
def test_stack_pop(self):
s = Stack()
s.push('a')
s.push('b')
s.push('c')
self.assertEqual(s.pop(), 'c')
def test_stack_push(self):
s = Stack()
s.push('a')
s.push('b')
s.push('c')
self.assertEqual(s.size, 3)
class Processor(object):
def __init__(self):
'''Creates the lists'''
self.callahead = DoublyLinkedList()
self.waiting = DoublyLinkedList()
self.appetizers = Queue()
self.buzzers = Stack()
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.buzzers.push('Buzzer')
self.songs = CircularLinkedList()
self.songs.add('Song 1')
self.songs.add('Song 2')
self.songs.add('Song 3')
self.songs_iter = CircularLinkedListIterator(self.songs)
def run(self, f):
'''Processes the given file stream.'''
for line_i, line in enumerate(f):
line = line.rstrip()
# split and handle the commands here
print('{}:{}'.format(line_i, line))
parts = line.split(',')
# call this command's function
try:
func = getattr(self, 'cmd_{}'.format(parts[0].lower()))
func(*parts[1:])
except Exception as e:
print('Error: {}'.format(e))
def cmd_debug(self, *args):
self.callahead.debug_print()
self.waiting.debug_print()
self.appetizers.debug_print()
self.buzzers.debug_print()
self.songs.debug_print()
def cmd_song(self, *args):
print(self.songs_iter.next())
def cmd_appetizer(self, *args):
app = self.appetizers.dequeue()
i = self.waiting.size - 1
values = []
if self.waiting.size >= 3:
while i >= self.waiting.size - 3:
values.append(self.waiting.get(i))
i -= 1
elif self.waiting.size == 2:
while i >= self.waiting.size - 2:
values.append(self.waiting.get(i))
i -= 1
elif self.waiting.size == 1:
while i >= self.waiting.size - 1:
values.append(self.waiting.get(i))
i -= 1
else:
values.append(self.waiting.get(i))
print('{} >>> {}'.format(app, ', '.join(values)))
def cmd_appetizer_ready(self, *args):
self.appetizers.enqueue(args[0])
def cmd_call(self, *args):
self.callahead.add(args[0])
def cmd_arrive(self, *args):
# check if they were on the callin list
callaheadSize = self.callahead.size
waitingSize = self.waiting.size
callahead = False
self.buzzers.pop()
i = 0
while i < callaheadSize:
if self.callahead.get(i) == args[0]:
self.callahead.delete(i)
callahead = True
break
i += 1
if callahead:
if waitingSize <= 5:
self.waiting.insert(0, args[0])
else:
self.waiting.insert(waitingSize - 4, args[0])
else:
self.waiting.add(args[0])
def cmd_seat(self, *args):
try:
print(self.waiting.get(0))
self.waiting.delete(0)
self.buzzers.push('Buzzer')
except:
raise IndexError(
'The given index is not within the bounds of the current list.'
)
def cmd_leave(self, *args):
self.buzzers.push('Buzzer')
waitingSize = self.waiting.size
i = 0
while i < waitingSize:
if self.waiting.get(i) == args[0]:
self.waiting.delete(i)
break
i += 1