def reverseList(L1):
reverseL1 = LinkedList()
current = L1.head
while current != None:
reverseL1.addNode(current.value)
current = current.next
return reverseL1
def reverseList(L1): reverseL1 = LinkedList() current = L1.head while current != None: reverseL1.addNode(current.value) current = current.next return reverseL1
def addLists_rev(L1, L2):
p1 = L1.head
p2 = L2.head
carry = 0
linkedlist_sum = LinkedList()
while (p1 != None) or (p2 != None) or (carry != 0):
dig_sum = carry
if p1 != None:
dig_sum += p1.value
p1 = p1.next
if p2 != None:
dig_sum += p2.value
p2 = p2.next
linkedlist_sum.addNode(dig_sum % 10)
carry = dig_sum / 10
return linkedlist_sum
def addLists_rev(L1, L2):
p1 = L1.head
p2 = L2.head
carry = 0
linkedlist_sum = LinkedList()
while (p1 != None) or (p2 != None) or (carry != 0):
dig_sum = carry
if p1 != None:
dig_sum += p1.value
p1 = p1.next
if p2 != None:
dig_sum += p2.value
p2 = p2.next
linkedlist_sum.addNode(dig_sum%10)
carry = dig_sum/10
return linkedlist_sum
current = linkedlist.head
while current != None:
length += 1
current = current.next
return length
# -------------------test------------------
L1 = randomLinkedList(3, 3, 4)
print "L2:", L1
print "isPalindrome_iter: ", isPalindrome_iter(L1)
print "isPalindrome_recu: ", isPalindrome_recu(L1)
L2 = LinkedList()
for i in range(1,4):
L2.addNode(i)
for i in range(3, 0, -1):
L2.addNode(i)
print "L3:", L2
print "isPalindrome_iter: ", isPalindrome_iter(L2)
print "isPalindrome_recu: ", isPalindrome_recu(L2)
# Another method: reverse the list and check if they are the same
def isPalindrome(L1):
reverseL1 = reverseList(L1)
return isEqual(L1, reverseL1)
def reverseList(L1):
reverseL1 = LinkedList()
current = L1.head
while current != None:
return None
# Move one runner to head. Making them move at same pace, they will meet at the beginning of the loop
fast = linkedlist.head
while fast != slow:
slow = slow.next
fast = fast.next
return fast
# -----------------test------------------
nodes_number = 100
nodes_in_loop = 20
L = LinkedList()
current = L.head
store = [] # store nodes to help creating loop
# Create a linked list
for i in range(nodes_number):
L.addNode(i)
current = L.head if i == 0 else current.next
store.append(current)
# Creat loop
current.next = None if nodes_in_loop <= 0 else store[nodes_number -
nodes_in_loop]
beginning = findBeginning(L)
print beginning # 80
from classes.LinkedList import *
def isPalindrome(linkedlist):
if linkedlist.head == None:
return None
fast = linkedlist.head
slow = linkedlist.head
firsthalf = []
while fast != None and fast.next != None:
firsthalf.append(slow.value)
slow = slow.next
fast = fast.next.next
if fast != None:
slow = slow.next
while slow != None:
if firsthalf.pop() != slow.value:
return False
else:
slow = slow.next
return True
L1 = randomLinkedList(3, 3, 4)
print "L2:", L1
print "Is Palindrome? ", isPalindrome(L1)
L2 = LinkedList()
for i in range(1,4):
L2.addNode(i)
for i in range(3, 0, -1):
L2.addNode(i)
print "L3:", L2
print "Is Palindrome? ", isPalindrome(L2)
return None
# Move one runner to head. Making them move at same pace, they will meet at the beginning of the loop
fast = linkedlist.head
while fast != slow:
slow = slow.next
fast = fast.next
return fast
# -----------------test------------------
nodes_number = 100
nodes_in_loop = 20
L = LinkedList()
current = L.head
store = [] # store nodes to help creating loop
# Create a linked list
for i in range(nodes_number):
L.addNode(i)
current = L.head if i==0 else current.next
store.append(current)
# Creat loop
current.next = None if nodes_in_loop <= 0 else store[nodes_number - nodes_in_loop]
beginning = findBeginning(L)
print beginning # 80
def randomLinkedList(length, min, max):
linkedlist = LinkedList()
for i in range(length):
value = randint(min, max)
linkedlist.addNode(value)
return linkedlist
