class LinklistStack(object):
def __init__(self):
self._data = LinkList()
def __len__(self):
return self._data.size
def is_empty(self):
return self._data.size == 0
def push(self, value):
return self._data.add_first(value)
def pop(self):
if self.is_empty():
raise ValueError('Stack is empty')
return self._data.remove_first()
def top(self):
if self.is_empty():
raise ValueError('Stack is empty')
return self._data.head.next.value
def printstack(self):
return self._data.print_list()
from linklist_f import LinkList
def find_mid(llist):
assert llist.head is not None and llist.head.next is not None
fast = llist.head
slow = llist.head
while fast is not None and fast.next is not None:
fast = fast.next.next
slow = slow.next
return slow.value
if __name__ == '__main__':
ll = LinkList()
ll.add_first(1)
ll.add_last(2)
ll.add_last(3)
ll.print_list()
if ll.head is not None:
print('right')
result = find_mid(ll)
print(result)