Eliminate duplicates from Linked List using C++ program

To solve this problem, we keep the temp pointer pointing to node. While(temp -> next != NULL), we check if the data of temp is equal to data of temp->next. If they are equal, we will point the temp-> next to temp -> next ->next.
Original LL: 3-> 3-> 4-> ...
After Change: 3-> 4-> ... Leaving out the middle 3->

This will keep on until we reached the end of the list and return head at the end.

Steps

    1.	1->2->3->3->4->4->4->NULL, temp = 1
    2.	1->2->3->3->4->4->4->NULL, temp = 2
    3.	1->2->3->3->4->4->4->NULL, temp = 3
    4.	1->2->3->4->4->4->NULL, temp = 4
    5.	1->2->3->4->4->NULL, temp = 4
    Finally,
    1->2->3->4->NULL

Function:

Node *removeDuplicate(Node* head){
	//temp pointing to head
	Node *temp = head;            
	while(temp->next != NULL && temp != NULL){
		//Duplicate Found
		if(temp->data == temp->next->data){      
			//DUplicate Removed
			temp -> next = temp ->next ->next;    
		}
		else{
			//No Duplicate Present
			temp = temp->next;               
		}
	}
	//Return Head
	return head;                
}

C++ Code:

#include<bits/stdc++.h>
using namespace std;

struct Node{// linked list Node
	int data;
	Node * next;
};

Node *newNode(int k){ //defining new node
	Node *temp = (Node*)malloc(sizeof(Node)); 
	temp->data = k; 
	temp->next = NULL; 
	return temp; 
}

//Used to add new node at the end of the list
Node *addNode(Node* head, int k){
	if(head == NULL){
		head = newNode(k);
	}
	else{
		Node * temp = head;
		Node * node = newNode(k);
		while(temp->next!= NULL){
			temp = temp->next;
		}
		temp-> next = node;
	}

	return head;
}

// Used to create new linked list and return head
Node *createNewLL(){
	int cont = 1;
	int data;
	Node* head = NULL;
	while(cont){
		cout<<"Enter the data of the Node"<<endl;
		cin>>data;
		head = addNode(head,data);
		cout<<"Do you want to continue?(0/1)"<<endl;
		cin>>cont;
	}
	return head;
}

//To print the Linked List
void *printLL(Node * head){
	while(head!= NULL){
		cout<<head->data<<"->";
		head = head-> next;
	}
	cout<<"NULL"<<endl;
}

//Function 
Node *removeDuplicate(Node* head){
	//temp pointing to head
	Node *temp = head;
	while(temp->next != NULL && temp != NULL){
		//Duplicate Found
		if(temp->data == temp->next->data){
			//DUplicate Removed
			temp -> next = temp ->next ->next;
		}
		else{
			//No Duplicate Present
			temp = temp->next;
		}
	}
	//Return Head
	return head;
}

//Driver Main
int main(){
	Node * head = createNewLL();
	cout<<"The linked list is"<<endl;
	printLL(head);

	head = removeDuplicate(head);
	cout<<"The new Linked List is" <<endl;
	printLL(head);

	return 0;
}

Output

Enter the data of the Node
1
Do you want to continue?(0/1)
1
Enter the data of the Node
1
Do you want to continue?(0/1)
1
Enter the data of the Node
2
Do you want to continue?(0/1)
1
Enter the data of the Node
2
Do you want to continue?(0/1)
1
Enter the data of the Node
3
Do you want to continue?(0/1)
1
Enter the data of the Node
4
Do you want to continue?(0/1)
1
Enter the data of the Node
5
Do you want to continue?(0/1)
1
Enter the data of the Node
5
Do you want to continue?(0/1)
1
Enter the data of the Node
5
Do you want to continue?(0/1)
0
The linked list is
1->1->2->2->3->4->5->5->5->NULL
The new Linked List is
1->2->3->4->5->NULL