题解 | #删除有序链表中重复的元素-II#

package main
import . "nc_tools"
/*
 * type ListNode struct{
 *   Val int
 *   Next *ListNode
 * }
 */

/**
  * 
  * @param head ListNode类 
  * @return ListNode类
*/
func deleteDuplicates( head *ListNode ) *ListNode {
    // write code here
    
    if head == nil || head.Next == nil  {
        return head 
    }
    
    ht1 := make(map[int]bool)
    ht2 := make(map[int]bool)
    
    tmp := head 
    for tmp != nil {
        if ht1[tmp.Val] {
            ht2[tmp.Val] = true 
        }
        ht1[tmp.Val] = true  
        tmp = tmp.Next 
    }
    
    tmp = head 
    for tmp != nil && ht2[tmp.Val] {
        tmp = tmp.Next 
    }
    
    head = tmp 
    tmp = head 
    
    for tmp != nil {
        for tmp.Next != nil && ht2[tmp.Next.Val] {
            tmp.Next = tmp.Next.Next
        }
        tmp = tmp.Next 
    }
    
    return head 
}