LeetCode 83. Delete duplicate elements in the sorting linked list

Title Description

83. Delete duplicate elements from the sort list

solution

A set of fast and slow pointers is done

/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode() : val(0), next(nullptr) {} * ListNode(int x) : val(x), next(nullptr) {} * ListNode(int x, ListNode *next) : val(x), next(next) {} * }; */
class Solution {
    
public:
    ListNode* deleteDuplicates(ListNode* head) {
    
        if (head == nullptr) return nullptr;
        ListNode* slow = head;
        ListNode* fast = head;
        while (fast != nullptr)
        {
    
            if (fast->val != slow->val)
            {
    
                slow->next = fast;
                slow = slow->next;
            }
            fast = fast->next;
        }
        slow->next = nullptr;
        return head;
    }
};