python/linkedlist.py at main · yadavrahulrao/python · 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
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
#traversal of a linked list

# class Node:
#   def __init__(self, data):
#     self.data = data
#     self.next = None

# def traverseAndPrint(head):
#   currentNode = head
#   while currentNode:
#     print(currentNode.data, end=" -> ")
#     currentNode = currentNode.next
#   print("null")

# node1 = Node(7)
# node2 = Node(11)
# node3 = Node(3)
# node4 = Node(2)
# node5 = Node(9)

# node1.next = node2
# node2.next = node3
# node3.next = node4
# node4.next = node5

# traverseAndPrint(node1)


# find the lowest value in a linked list

# class Node:
#   def __init__(self,data):
#     self.data = data
#     self.next = None

# def thelowest(head):
#   minvalue = head.data
#   curr = head.next
#   while curr:
#     if curr.data < minvalue:
#       minvalue = curr.data
#     curr = curr.next
#   return minvalue

# n1 = Node(5)
# n2 = Node(11)
# n3 = Node(4)
# n4 = Node(1)
# n5 = Node(3)

# n1.next = n2
# n2.next = n3
# n3.next = n4
# n4.next = n5


# print(thelowest(n1))


# delete a node from a linked list

# class Node :
#   def __init__(self,data):
#     self.data = data
#     self.next = None

# def traverse(head):
#   curr = head
#   while curr:
#     print(curr.data,end='-->')
#     curr = curr.next
#   print("null")

# def deletenode(head,node):
#   if head == node:
#     return head.next
#   curr = head
#   while curr.next and curr.next != node:
#     curr = curr.next

#   if curr.next == None:
#     return head

#   curr.next = curr.next.next
#   return head

# n1 = Node(2)
# n2 = Node(4)
# n3 = Node(5)
# n4 = Node(6)
# n5 = Node(8)

# n1.next = n2
# n2.next = n3
# n3.next = n4
# n4.next = n5

# traverse(n1)

# n1 = deletenode(n1,n4)

# traverse(n1)


# insert a node in a linked list


class Node:
  def __init__(self,data):
    self.data = data
    self.next = None

def traverse(head):
  curr = head
  while curr:
    print(curr.data,end="-->")
    curr = curr.next
  print("null")

def insertnode(head,node,pos):
  if pos == 1:
    node.next = head
    return node
  curr = head
  for _ in range(pos-2):
    if curr is None:

      break
    curr = curr.next
  node.next = curr.next
  curr.next = node
  return head

n1 = Node(1)
n2 = Node(2)
n3 = Node(3)
n4 = Node(4)
n5 = Node(5)

n1.next = n2
n2.next = n3
n3.next = n4
n4.next = n5

traverse(n1)

node = Node(67)

n1 = insertnode(n1,node , 3)

traverse(n1)