83. Remove Duplicates from Sorted List

Given a sorted linked list, delete all duplicates such that each element appear only once.

For example,
Given 1->1->2, return 1->2.
Given 1->1->2->3->3, return 1->2->3.

Solution:

The idea is to iterate through the Linked List and check if the adjacent nodes have the same value.

If so, we point the next of the current node to the next of its next.


Code:

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
public class Solution {
    public ListNode deleteDuplicates(ListNode head) {
        ListNode curr = head;
        while (curr != null && curr.next != null ) {
            if (curr.val == curr.next.val) {
                curr.next = curr.next.next;
            }
            else {
                curr = curr.next;
            }
        }
        return head;
    }
}