Intersection of Two Linked Lists

# Definition for singly-linked list.
# class ListNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution(object):
    def getIntersectionNode(self, headA, headB):
        """
        :type head1, head1: ListNode
        :rtype: ListNode
        """
        if not headA or not headB:
            return None

        # Initialize two pointers
        pointerA, pointerB = headA, headB

        # Traverse both lists; switch to the other head when reaching the end
        while pointerA != pointerB:
            pointerA = pointerA.next if pointerA else headB
            pointerB = pointerB.next if pointerB else headA

        # Either they meet at the intersection node or at the end (None)
        return pointerA