Remove Duplicates From Sorted List Problem Solution

Remove Duplicates From Sorted List: 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.

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

Remove Duplicates From Sorted List Problem Solution

Problem Solution In Python

class Solution:
    def deleteDuplicates(self, head: ListNode) -> ListNode:
        if not head:
            return
        current = head
        if current:
            while current.next and current:
                # print(current.val)
                if current.val == current.next.val:
                    current.next = current.next.next
                else:
                    current= current.next
        return head

Problem Solution In Java

public ListNode deleteDuplicates(ListNode head) {
        ListNode dummy = head;
        while(dummy != null && dummy.next !=null){
            if(dummy.val == dummy.next.val) dummy.next = dummy.next.next;
            else dummy = dummy.next;
        }
        return head;
    }

Problem Solution In C++

class Solution {
public:
    ListNode* deleteDuplicates(ListNode* head) {
        if (head==nullptr)
            return 0;
        struct ListNode* ptr;
        ptr=head;
        while (ptr->next != nullptr){
            if (ptr->val ==ptr->next->val){
                ptr->next=ptr->next->next;
            }
            else
               ptr=ptr->next;
        }
        return head;
        
    }
};

Problem Solution In C

struct ListNode* deleteDuplicates(struct ListNode* head){
    
    struct ListNode* cur = head;
    if(head == NULL)
        return head;
    
    while(cur->next != NULL)
    {
        if(cur->val == (cur->next->val))
        {
            cur->next = cur->next->next;
        }
        else
            cur = cur->next;
    }
    
    return head;

}