Compiler/util.py at master · sambodanis/Compiler · GitHub

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
__author__ = 'sambodanis'


class Node:
    def __init__(self, data, next):
        self.data = data
        self.next = next

    def __str__(self):
        print self.data


class Stack:
    def __init__(self):
        self.top = None
        self.count = 0

    def __str__(self):
        c = self.top
        res = []
        while True:
            if c is None:
                break
            res.append(c.data)
            c = c.next
        return '[' + ', '.join(res) + ']'

    def push(self, item):
        if self.top is None:
            self.top = Node(item, None)
        else:
            new = Node(item, self.top)
            self.top = new
        self.count += 1

    def pop(self):
        if self.top is not None:
            result = self.top.data
            self.top = self.top.next
            self.count -= 1
            return result
        else:
            return None

    def peek(self):
        if self.count == 0:
            return None
        return self.top.data

    def size(self):
        return self.count

    def is_empty(self):
        return self.count == 0


class Queue:
    def __init__(self):
        self.first = None
        self.last = None
        self.count = 0

    def enqueue(self, item):
        if self.first is None:
            self.last = Node(item, None)
            self.first = self.last
        else:
            self.last.next = Node(item, None)
            self.last = self.last.next
        self.count += 1

    def dequeue(self):
        if self.first is not None:
            result = self.first.data
            self.first = self.first.next
            self.count -= 1
            return result
        return None

    def peek(self):
        if self.count == 0:
            return None
        return self.first.data

    def size(self):
        return self.count

    def is_empty(self):
        return self.count == 0