题目
给定一个排序链表，删除所有重复的元素，使得每个元素只出现一次。
示例1
输入: 1->1->2
输出: 1->2
示例2
输入: 1->1->2->3->3
输出: 1->2->3
定义节点
class ListNode {
public var val: Int
public var next: ListNode?
public init(_ val: Int) {
self.val = val
self.next = nil
}
}
解法
func deleteDuplicates(_ head: ListNode?) -> ListNode? {
var current = head
var next = head?.next
while next != nil {
if current?.val == next?.val {
current?.next = next?.next
next = next?.next
}
else {
current = next
next = next?.next
}
}
return head
}
