面试题 02.01. 移除重复节点

Posted 2022-12-02 深林无鹿

hash(O(n))

/**
 * Definition for singly-linked list.
 * public class ListNode 
 *     int val;
 *     ListNode next;
 *     ListNode(int x)  val = x; 
 * 
 */
class Solution 
    public ListNode removeDuplicateNodes(ListNode head) 
        int[] hash = new int[20005];
        ListNode prev = head, curr = head;
        while (curr != null) 
            if (hash[curr.val] == 0) 
                hash[curr.val] ++;
                prev = curr;
             else 
                prev.next = curr.next;
            
            curr = curr.next;
        
        return head;