class Queue(object):
'''
A linked list implementation of a queue.
This contains a LinkedList internally. It does not extend LinkedList.
In other words, this class uses "Composition" rather than "Inheritance".
'''
def __init__(self):
'''Constructor'''
self.queue = LinkedList()
def debug_print(self):
'''Prints a representation of the entire queue.'''
self.queue.debug_print()
def enqueue(self, item):
'''Adds an item to the end of the queue'''
self.queue.add(item)
def dequeue(self):
'''
Dequeues the first item from the list. This involves the following:
1. Get the first node in the list.
2. Delete the node from the list.
3. Return the value of the node.
'''
beg = self.queue._get_node(0)
self.queue.delete(0)
return beg.value
def size(self):
'''Returns the number of items in the queue'''
return self.queue.size
class Processor(object):
def run(self, f):
'''Processes the given file stream.'''
for line_i, line in enumerate(f):
# get the line parts
line = line.rstrip()
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.ll.debug_print()
def cmd_create(self, *args):
self.ll = LinkedList()
def cmd_add(self, *args):
self.ll.add(args[0])
def cmd_insert(self, *args):
self.ll.insert(int(args[0]), args[1])
def cmd_set(self, *args):
self.ll.set(int(args[0]), args[1])
def cmd_get_node(self, *args):
print(self.ll._get_node(int(args[0])))
def cmd_delete(self, *args):
self.ll.delete(int(args[0]))
def cmd_swap(self, *args):
self.ll.swap(int(args[0]), int(args[1]))
def cmd_get(self, *args):
self.ll.get(int(args[0]))