ccup2_1_follow_up

/*
  When a temperary buffer is not allowed, the function directly operates on the list.
  From the beginning, the element is compared with the following ones every time. When there is the duplicate one, delete it.
  Time complexity O(n^2)
  Space compexity O(1)
*/
#include <stdio.h>
#include <vector>
#include <list>
#include <iostream>

using namespace std;

list deleteDupl(list list1)
{
  list<int>::iterator l1,l2;
  int flag=0;
  
  for(l1=list1.begin();l1!=list1.end();l1++)
	{
		
		for(l2=l1;l2!=list1.end();l2++)
		{
			l2++;
			if(l2==list1.end())
				break;
			if((*l1)==(*l2))
			{
				flag=1;
				break;
			}
		}
		if(flag==1)
		{
			list1.erase(l2);
			flag=0;
		}
	}
	return list1;
}