sol_045.md

Remove Duplicates from Sorted List - Practice - LeetCode

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]

Solution 1

Time - O(N)
Space - O(1)

class Solution {
public:
    ListNode* deleteDuplicates(ListNode* head) {
        if (head== nullptr) return head;        
        
        ListNode *curr = head;        

        while(curr && curr->next){
            if (curr->val == curr->next->val)
                curr->next = curr->next->next;
            else
                curr = curr->next;
        }
        return head;        
    }
};