#include "chapter2.hpp"
#include <unordered_map>

/*
Remove Dups!
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?
 */

void remove_dups(DopeLinkedList* ll){
  DopeNode* prev = ll->GetHead();
  DopeNode* node = ll->GetHead();
  DopeNode* tmp = NULL;
  std::unordered_map<int, int> dup_tracker;
  int iter_cnt = 0;

  while(node->GetNext() != NULL){
    if(dup_tracker.count(node->GetData())){
      // remove node
      prev->SetNext(node->GetNext());
      tmp = node;
      node = node->GetNext();
      tmp->Reset();
    } else {
      dup_tracker[node->GetData()] += 1;
      node = node->GetNext();
      if (iter_cnt != 0){
        prev = prev->GetNext();
      }
    }

    iter_cnt++;
  }
}