def intersection_list(head1, head2):
ll = LinkedList()
cur1 = head1
cur2 = head2
while cur1 and cur2:
if cur1.data < cur2.data:
cur1 = cur1.next
elif cur1.data > cur2.data:
cur2 = cur2.next
else:
ll.insert_at_ending(cur2.data)
cur1 = cur1.next
cur2 = cur2.next
return ll
new.next = cur1
cur1 = cur1.next
new = new.next
while cur2 :
new.next = cur2
cur2 = cur2.next
new = new.next
new.next = None
return head
def insert_at_ending(last,node):
if not last :
return node
else :
last.next = node
return node
if __name__=='__main__':
ll1 = LinkedList()
for i in range(1,15):
ll1.insert_at_ending(i)
ll2 = LinkedList()
for j in range(11,19):
ll2.insert_at_ending(j)
head = merge_sortedlists(ll2.head,ll1.head)
current = head
while current :
print(current.data)
current = current.next
current = head
next = None
prev = None
count = 0
while current and count < k:
next = current.next
current.next = prev
prev = current
current = next
count += 1
if next:
head.next = current
count = 0
while current and count < k - 1:
current = current.next
count += 1
if current:
current.next = reverse_alt_knodes(current.next, k)
return prev
if __name__ == '__main__':
ll = LinkedList()
for i in range(1, 10):
ll.insert_at_ending(i)
ll.head = reverse_alt_knodes(ll.head, 3)
ll.print_list()
from GeeksForGeeks.LinkedList.SinglyLinkedList import LinkedList
"""
function a revervse a linkedlist
"""
def reverse_ll(head):
"""
reversing the pointers for every node - Single traveral - O(n) time.
:param head
:return:
"""
prev = None
current = head
while current:
temp = current.next
current.next = prev
prev = current
current = temp
return prev
if __name__ == '__main__':
ll = LinkedList()
for i in range(5, 9):
ll.insert_at_ending(i)
ll.print_list()
ll.head = reverse_ll(ll.head)
ll.print_list()
from GeeksForGeeks.LinkedList.SinglyLinkedList import LinkedList
"""
Move last element to front of a given Linked List
Write a C function that moves last element to front in a given Singly Linked List. For example, if the given Linked
List is 1->2->3->4->5, then the function should change the list to 5->1->2->3->4.
"""
def move_nth(head):
if not head:
return
else:
current = head
prev = head
while current.next is not None:
prev = current
current = current.next
prev.next = None
current.next = head
head = current
return head
if __name__ == '__main__':
ll = LinkedList()
for i in range(1, 10):
ll.insert_at_ending(i)
ll.head = move_nth(ll.head)
ll.print_list()
from GeeksForGeeks.LinkedList.SinglyLinkedList import LinkedList
"""
Delete alternate nodes of a Linked List
Given a Singly Linked List, starting from the second node delete all alternate nodes of it.
For example, if the given linked list is 1->2->3->4->5 then your function should convert it to 1->3->5,
and if the given linked list is 1->2->3->4 then convert it to 1->3.
"""
def delete_alternate_node(node):
if not node:
return
else:
current = node
while current.next:
current.next = current.next.next
current = current.next
if __name__ == '__main__':
ll = LinkedList()
for i in range(1, 6):
ll.insert_at_ending(i)
delete_alternate_node(ll.head)
ll.print_list()
def delete_nodes(head):
if not head:
return
else:
new_head = reverse(head)
current = new_head
_max = current.data
while current and current.next:
if current.next.data < _max and current.next:
current.next = current.next.next
else:
_max = current.data
current = current.next
head1 = reverse(new_head)
return head1
if __name__ == '__main__':
ll = LinkedList()
ll.insert_at_ending(12)
ll.insert_at_ending(15)
ll.insert_at_ending(10)
ll.insert_at_ending(11)
ll.insert_at_ending(5)
ll.insert_at_ending(6)
ll.insert_at_ending(2)
ll.insert_at_ending(3)
ll.head = delete_nodes(ll.head)
ll.print_list()
cur1 = head1
cur2 = head2
while cur1 and cur2:
if cur1.data != cur2.data:
return False
else:
cur1 = cur1.next
cur2 = cur2.next
if cur1:
return False
if cur2:
return False
return True
if __name__ == '__main__':
ll = LinkedList()
for i in range(1, 10):
ll.insert_at_ending(i)
l2 = LinkedList()
for i in range(1, 10):
l2.insert_at_ending(i)
l3 = LinkedList()
for j in range(1, 5):
l3.insert_at_ending(j)
print(check_identical(ll.head, l2.head))
print(check_identical(l2.head, l3.head))
print(is_identical(ll.head, l2.head))
print(is_identical(l2.head, l3.head))
from GeeksForGeeks.LinkedList.SinglyLinkedList import LinkedList
def remove_duplicates(head):
if not head:
return
else:
current = head
while current and current.next:
if current.data == current.next.data:
current.next = current.next.next
current = current.next
if __name__ == '__main__':
ll = LinkedList()
for i in range(1, 10):
ll.sorted_insert(i)
for i in range(1, 10):
ll.sorted_insert(i)
ll.print_list()
print('break')
remove_duplicates(ll.head)
ll.print_list()
prev = None
next = None
while current and count < k :
next = current.next
current.next = prev
prev = current
current = next
count += 1
if next :
head.next = reverse_in_groups(next,k)
return prev
if __name__=='__main__':
ll = LinkedList()
for i in range(1,3):
ll.insert_at_ending(i)
ll.head = reverse(ll.head)
#ll.print_list()
ll.head = reverse(ll.head)
ll.head = reverse_in_groups(ll.head,1)
ll.print_list()
"""
def getNthNode(head,n):
"""
function to return nth node from the start in a singly linkedlist
:param head:
:param n: nth node
:return:
"""
if not head :
return None
count = 0
temp = head
while temp and count < n:
temp = temp.next
count += 1
if temp :
return temp.data
else :
return temp
if __name__=="__main__":
ll = LinkedList()
for i in range(1,10):
ll.insert_at_begining(i)
print(getNthNode(ll.head,5))
xt
return node
current = node.next
prev = node
node = current
while prev and current :
next = current.next
current.next = prev
if not next or not next.next :
prev.next = next
break
prev.next = next.next
prev = next
current = prev.next
return node
if __name__=='__main__':
ll = LinkedList()
for i in range(1,10):
ll.insert_at_ending(i)
#ll.print_list()
#pairwise_swap(ll.head)
#ll.print_list()
ll.head = _pairwise_swap(ll.head)
ll.print_list()
def addsamesize(head1, head2):
if not head1 and not head2:
return None, 0
else:
node = Node()
node.next, carry = addsamesize(head1.next, head2.next)
_sum = head1.data + head2.data + carry
carry = _sum // 10
_sum = _sum % 10
node.data = _sum
return node, carry
if __name__ == '__main__':
l1 = LinkedList()
l1.insert_at_ending(5)
l1.insert_at_ending(6)
l1.insert_at_ending(3)
l1.insert_at_ending(3)
l2 = LinkedList()
l2.insert_at_ending(8)
l2.insert_at_ending(4)
l2.insert_at_ending(2)
#head = add_numbers(l1.head,l2.head)
#print_ll(head)
root = addnumbers(l1.head, l2.head)
print_ll(root)
current = current.next
while cur2:
_sum = cur2.data + carry
carry = _sum // 10
_sum = _sum % 10
current.next = Node(_sum)
cur2 = cur2.next
current = current.next
if carry == 1:
current.next = Node(carry)
return new_head
if __name__ == '__main__':
ll1 = LinkedList()
ll1.insert_at_ending(3)
ll1.insert_at_ending(6)
ll1.insert_at_ending(5)
ll2 = LinkedList()
ll2.insert_at_ending(2)
ll2.insert_at_ending(4)
ll2.insert_at_ending(8)
ll = LinkedList()
ll.head = add(ll1.head, ll2.head)
ll.print_list()
