-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathss_list.py
155 lines (143 loc) · 3.11 KB
/
ss_list.py
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
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
class list_node:
def __init__(self, data, nxt, prev):
self.data = data
self.nxt = nxt
self.prev = prev
def get_nxt(self):
return self.nxt
def get_prev(self):
return self.prev
def get_data(self):
return self.data
def set_prev(self, prev):
self.prev = prev
def set_nxt(self, nxt):
self.nxt = nxt
def set_data(self, data):
self.data = data
class locallist:
def __init__(self):
print "Creating a new list"
self.head=None
def append(self, data):
node = list_node(data, None, None)
if self.head == None:
print "List seems empty"
self.head = node
node.set_nxt(node)
node.set_prev(node)
else:
print "Adding new data"
node.set_nxt(self.head)
head_prev = self.head.get_prev()
self.head.set_prev(node)
node.set_prev(head_prev)
head_prev.set_nxt(node)
#print "*****************"
#print node.get_data()
#print node.get_prev().get_data()
#print node.get_nxt().get_data()
#print "****************"
def insert(self, node, data):
if node == None:
print "Error: node data is empty"
return None
new = list_node(data, node.get_nxt(), node)
node_nxt = node.get_nxt()
node_nxt.set_prev(new)
node.set_nxt(new)
#print "******insert***********"
#print new.get_data()
#print new.get_prev().get_data()
#print new.get_nxt().get_data()
#print "****************"
return new
def reverse(self):
if self.head == None:
print "Error: reverse on Empty List"
return
cur = self.head
fut = None
nxt = None
prv = None
while(fut != self.head):
fut = cur.get_nxt()
nxt = cur.get_nxt()
prv = cur.get_prev()
cur.set_nxt(prv)
cur.set_prev(nxt)
cur = fut
self.head = self.head.get_nxt()
def get_data(self, node):
if self.head == None:
print "Error: Empty List"
return None
if node == None:
return self.head.get_data()
return node.get_data()
def go_nxt(self, node):
if node == None:
if self.head != None:
return self.head
else:
print("Error: Empty List")
return None
return node.get_nxt()
def go_prev(self, node):
if node == self.head:
return None
if node == None:
print("Error: Empty List")
return node.get_prev()
def get_head(self):
return self.head
def print_list(self):
cur = self.head
while 1:
print "data {}".format(cur.get_data())
#print "prev {}".format(cur.get_prev().get_data())
#print "nxt {}".format(cur.get_nxt().get_data())
cur = cur.get_nxt()
if cur == self.head:
break
"""
i = locallist()
i.append(1)
i.append(2)
i.append(3)
i.append(4)
n = i.go_nxt(None)
print i.get_data(n)
n = i.go_nxt(n)
print i.get_data(n)
n = i.go_nxt(n)
print i.get_data(n)
n = i.go_nxt(n)
print i.get_data(n)
i.insert(n,5)
n = i.go_nxt(n)
print i.get_data(n)
i.append(6)
print "****************"
i.print_list()
print "****************"
i.reverse()
i.print_list()
print "-----again reverse----"
i.reverse()
i.print_list()
# print i.get_data(None)
print "moving prev"
n = i.go_prev(n)
print i.get_data(n)
n = i.go_prev(n)
print i.get_data(n)
n = i.go_prev(n)
print i.get_data(n)
n = i.go_prev(n)
print i.get_data(n)
n = i.go_prev(n)
print i.get_data(n)
n = i.go_prev(n)
print i.get_data(n)
"""