Description
Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.
Return the linked list sorted as well.
Constraints
Approach
Links
Examples
Input: 1 -> 2 -> 3 -> 3 -> 4 -> 4 -> 5
Output: 1 -> 2 -> 5
Input: 1 -> 1 -> 1 -> 2 -> 3
Output: 2 -> 3
Solutions
/**
* Time complexity :
* Space complexity :
*/
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode deleteDuplicates(ListNode head) {
if(head == null) return null;
ListNode node = new ListNode(-1);
node.next = head;
ListNode curr = node;
while(curr.next != null && curr.next.next != null) {
if(curr.next.val == curr.next.next.val) {
int value = curr.next.val;
while(curr.next != null && curr.next.val == value) {
curr.next = curr.next.next;
}
} else {
curr = curr.next;
}
}
return node.next;
}
}
Follow up