Problem
Given the head of a sorted linked list, delete all duplicates such that each element appears only once. Return the linked list sorted as well.
Example 1:
Input: head = [1,1,2]
Output: [1,2]Example 2:
Input: head = [1,1,2,3,3]
Output: [1,2,3]Constraints:
- The number of nodes in the list is in the range
[0, 300]. 100 <= Node.val <= 100- The list is guaranteed to be sorted in ascending order.
Solution
/**
* Definition for singly-linked list.
* function ListNode(val, next) {
* this.val = (val===undefined ? 0 : val)
* this.next = (next===undefined ? null : next)
* }
*/
/**
* @param {ListNode} head
* @return {ListNode}
*/
var deleteDuplicates = function(head) {
let H = head;
while (H !== null) {
while (H.next !== null && H.val == H.next.val) {
H.next = H.next.next;
}
H = H.next;
}
return head;
};