[leetcode 链表] 反转链表 vs 链表相交

1. 反转链表 E

:::details

/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
func reverseList(head *ListNode) *ListNode {
    if head == nil || head.Next == nil {
        return head
    }
    var prev *ListNode
    cur := head
    next := head.Next
    for cur!= nil {
        next = cur.Next
        cur.Next = prev
        prev = cur
        cur = next
    }
    return prev
}

:::

2 链表相交 E

:::details

func getIntersectionNode(headA, headB *ListNode) *ListNode {
    if headA == nil || headB == nil {
        return nil
    }
    pa, pb := headA, headB
    for pa != pb {
        if pa == nil {
            pa = headB
        } else {
            pa = pa.Next
        }
        if pb == nil {
            pb = headA
        } else {
            pb = pb.Next
        }
    }
    return pa
}

:::