LeetCode 160. Intersection of Two Linked Lists 时间复杂度(O(n))

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本文介绍了一种高效查找两个单链表交点的算法，时间复杂度为O(n)。通过双指针技巧，无需额外空间即可找到两链表的第一个公共节点。

时间复杂度(O(n))，思想：指针位移

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

class Solution:
    def getIntersectionNode(self, headA, headB):
        pa, pb = headA, headB
        while pa != None and pb != None:
            pa, pb = pa.next, pb.next
        while pa != None:
            headA, pa = headA.next, pa.next
        while pb != None:
            headB, pb = headB.next, pb.next
        while headA != headB:
            headA, headB = headA.next, headB.next
        return headA