Careercup 2.1 - 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? Note: 1. pay special attention to deleting a node 2. learn to use "map" in C++ STL as a hash table

gistfile1.cpp

/*Remove duplicates from an unsorted linked list - cc2.1*/
void removeDuplicate1(node *head){
  map<int,bool> table;
	node *curr = head;
	node *pre = NULL;
	while(curr!=NULL){
		/*delete the node if it already exists in the map*/
		if(table[curr->data]){
			pre->next = curr->next;
			delete curr;
			curr = pre->next;
		}
		/*add the node to the table if it does not exist in the map before*/
		else{
			table[curr->data] = true;
			pre = curr;
			curr = curr->next;
		}
	}
}

void removeDuplicate2(node *head){
	node *curr = head;
	while(curr!=NULL){
		node *runner = curr->next;
		node *pre = curr;
		while(runner!=NULL){
			if(curr->data == runner->data){
				pre->next = runner->next;
				delete runner;
				runner = pre->next;
			}
			else{
				pre = runner;
				runner = runner ->next;
			}

		}
		curr = curr->next;
	}
}