1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95 | class Node:
"""
Node of Linked List
"""
def __init__(self, item=None, link=None):
self.data = item
self.next = link
class Stack:
"""
Stack Implementation using Linked List
"""
def __init__(self):
self.head = None
def push(self, item):
new_node = Node(item, self.head)
self.head = new_node
def pop(self):
if not self.isEmpty():
popped_node = self.head
if self.head.next:
self.head = self.head.next
else:
self.head = None
return popped_node.data
else:
raise IndexError("Trying to remove from empty stack!")
def isEmpty(self):
"""
Returns true if stack is empty, otherwise false
"""
return self.head == None
def size(self):
"""
Returns size of stack
"""
size = 0
temp = self.head
while temp:
size += 1
temp = temp.next
return size
def __str__(self):
temp = self.head
res = ''
while temp:
res += ' ' + str(temp.data)
temp = temp.next
return res
class Queue:
"""
Queue Implementation using Stack
"""
def __init__(self):
self.stack1 = Stack()
self.stack2 = Stack()
def enqueue(self, item):
while not self.stack1.isEmpty():
self.stack2.push(self.stack1.pop())
self.stack1.push(item)
while not self.stack2.isEmpty():
self.stack1.push(self.stack2.pop())
def dequeue(self):
removed_element = self.stack1.pop()
return removed_element
def __str__(self):
return str(self.stack1)
mstack = Stack()
mstack.push(9)
mstack.push(10)
print(mstack)
mstack.pop()
print(mstack)
mqueue = Queue()
mqueue.enqueue(9)
mqueue.enqueue(10)
print(mqueue)
mqueue.dequeue()
print(mqueue)
|