Syntax error Program to find linked list intersection from two linked list in Python

Program to find linked list intersection from two linked list in Python

Suppose we have two sorted linked lists L1 and L2, we have to make a new sorted linked list which contains the intersection of these two lists.

So, if the input is like L1 = [2, 4, 8] L2 = [3, 4, 8, 10], then the output will be [4, 8, ]

To solve this, we will follow these steps −

  • head := a new node with value 0
  • cur := head
  • while l1 and l2 are not empty, do
    • if value of l1 < value of l2, then
      • l1 := next of l1
    • otherwise when value of l2 < value of l1, then
      • l2 := next of l2
    • otherwise,
      • next of cur := a new node with value same as value of l1
      • l1 := next of l1
      • l2 := next of l2
      • cur := next of cur
  • return next of head

Let us see the following implementation to get better understanding −

Example

 Live Demo

class ListNode:
   def __init__(self, data, next = None):
      self.val = data
      self.next = next
def make_list(elements):
   head = ListNode(elements[0])
   for element in elements[1:]:
      ptr = head
      while ptr.next:
         ptr = ptr.next
      ptr.next = ListNode(element)
   return head
def print_list(head):
   ptr = head
   print('[', end = "")
   while ptr:
      print(ptr.val, end = ", ")
      ptr = ptr.next
   print(']')
class Solution:
   def solve(self, l1, l2):
      head = cur = ListNode(0)
      while l1 and l2:
         if l1.val < l2.val:
            l1 = l1.next
         elif l2.val < l1.val:
            l2 = l2.next
         else:
            cur.next = ListNode(l1.val)
            l1 = l1.next
            l2 = l2.next
            cur = cur.next
      return head.next
ob = Solution()
L1 = make_list([2, 4, 8])
L2 = make_list([3, 4, 8, 10])
print_list(ob.solve(L1, L2))

Input

[2, 4, 8], [3, 4, 8, 10]

Output

[4, 8, ]
Updated on: 2020-11-19T07:02:50+05:30

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