160. Intersection of Two Linked Lists

https://leetcode.com/problems/intersection-of-two-linked-lists/

solution

class Solution:
    def getIntersectionNode(self, headA: ListNode, headB: ListNode) -> Optional[ListNode]:
        l = []
        cur1 = headA
        while cur1 is not None:
            l.append(cur1)
            cur1 = cur1.next
        
        cur2 = headB
        while cur2 is not None:
            if cur2 in l:
                return cur2
            cur2 = cur2.next
        return None

时间复杂度：O() 空间复杂度：O()

class Solution:
    def getIntersectionNode(self, headA: ListNode, headB: ListNode) -> Optional[ListNode]:
        stackA = ['A']
        stackB = ['B']

        while headA or headB:
            if headA:
                stackA.append(headA)
                headA = headA.next

            if headB:
                stackB.append(headB)
                headB = headB.next

        prev = None
        while stackA and stackB:
            nodeA = stackA.pop(-1)
            nodeB = stackB.pop(-1)

            if nodeA != nodeB:
                return prev

            prev = nodeA