# Remove Duplicates from Sorted List Problem

## Description

LeetCode Problem 83.

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:

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Input: head = [1,1,2]
Output: [1,2]

Example 2:

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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.

## Sample C++ Code

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class Solution {
public:
ListNode* deleteDuplicates(ListNode* head) {
ListNode* currNode;
ListNode* prevNode;
if ((head == NULL) || (head->next == NULL))
return head;
prevNode = head;
currNode = head->next;
while (currNode != NULL) {
if (prevNode->val == currNode->val) {
currNode = currNode->next;
prevNode->next = currNode;
} else {
currNode = currNode->next;
prevNode = prevNode->next;
}
}
return head;
}
};