careercup2.1

/*Write code to remove duplicates from an unsorted linked list
FOLLOW UP
How would you solve this problem if a temporary buffer is not allowed?
*/
#include <iostream>
using namespace std;
class Node{
public:
int data;
Node* next;
Node(){this->next = 0;}
Node(int a):data(a),next(0){}
};

class LinkList{
public:
LinkList(){ head = new Node(-1);}
LinkList(int ar[],int len){
head = new Node(-1);
Node*p = FindTail();
for(int i = 0; i<len; i++)
insertion(ar[i]);
}
Node* FindTail();
Node* head;
void insertion(int);
Node* del(Node* i, Node*p);
void checkredu();
void print()const{
Node* p = head->next;
while(p)
{
cout<<p->data<<" ";
p = p->next;
}
}
};

Node* LinkList::FindTail(){
Node* p = head;
while( p->next!= 0){
p = p->next;
}
return p;
}
void LinkList::insertion(int k){
Node* p = FindTail();
p->next = new Node(k);
}

Node* LinkList::del(Node* i,Node*p){
p->next = i->next;
delete(i);
return p->next;
}

void LinkList::checkredu(){
Node* p = head->next;

while(p){
if(p->data == 67)
p = p;
Node* temp = p->next;
Node* par = p;
while(temp){
while(temp && temp->data == p->data)
{
temp = del(temp,par);
}
if(!temp) break; //tail cut
par = temp;
temp = temp->next;
}
p = p->next;
}
}
int main(){
int ar[]={1,3,5,67,8,9,45,78,9,33,12,3,5,4,67,67};
LinkList ll(ar,16);
ll.checkredu();
ll.print();
}