Remove Duplicates from Sorted List Solutions in C++

// Source : https://oj.leetcode.com/problems/remove-duplicates-from-sorted-list/
// Author : Hao Chen
// Date   : 2014-06-21



#include <stdio.h>

struct ListNode {
    int val;
    ListNode *next;
    ListNode(int x) : val(x), next(NULL) {}
};

ListNode *deleteDuplicates(ListNode *head) {

    for(ListNode *p=head; p && p->next; ){
        if (p->val == p->next->val){
            p->next = p->next->next;
            continue;
        }
        p=p->next;
    }
    return head;
}

void printList(ListNode* h)
{
    while(h!=NULL){
        printf("%d ", h->val);
        h = h->next;
    }
    printf("\n");
}

ListNode* createList(int a[], int n)
{
    ListNode *head=NULL, *p=NULL;
    for(int i=0; i<n; i++){
        if (head == NULL){
            head = p = new ListNode(a[i]);
        }else{
            p->next = new ListNode(a[i]);
            p = p->next;
        }
    }
    return head;
}


int main()
{
    int a[]={1,1,2,3,3};
    int b[]={1,1,1};

    printList(deleteDuplicates(createList(a, sizeof(a)/sizeof(int))));
    printList(deleteDuplicates(createList(b, sizeof(b)/sizeof(int))));
    return 0;
}

struct ListNode {
  int val;
  ListNode *next;
  ListNode(int x) : val(x), next(NULL) {}
};

class Solution {
public:
  ListNode *deleteDuplicates(ListNode *head) {
    for (ListNode *cur = head; cur && cur->next; )
    {
      if (cur->val == cur->next->val) 
      {
        ListNode *del = cur->next;
        cur->next = del->next;
        delete del;
      }
      else cur = cur->next;
    }    
    return head;
  }
};

/// Source : https://leetcode.com/problems/remove-duplicates-from-sorted-list/
/// Author : liuyubobobo
/// Time   : 2020-04-02

#include <iostream>

using namespace std;


/// Linear Scan
/// Time Complexity: O(n)
/// Space Complexity: O(1)

/// Definition for singly-linked list.
struct ListNode {
    int val;
    ListNode *next;
    ListNode(int x) : val(x), next(NULL) {}
};

class Solution {
public:
    ListNode* deleteDuplicates(ListNode* head) {

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


int main() {

    return 0;
}