remove-duplicates-from-sorted-list-ii.go

package problem0082

// ListNode is singly-linked list.
type ListNode struct {
	Val  int
	Next *ListNode
}

func deleteDuplicates(head *ListNode) *ListNode {
	// 长度 <=1 的 list ，可以直接返回
	if head == nil || head.Next == nil {
		return head
	}

	// 要么 head 重复了，那就删除 head
	if head.Val == head.Next.Val {
		for head.Next != nil && head.Val == head.Next.Val {
			head = head.Next
		}
		return deleteDuplicates(head.Next)
	}

	// 要么 head 不重复，递归处理 head 后面的节点
	head.Next = deleteDuplicates(head.Next)
	return head
}