UVA_11054_Wine trading in Gergovia

#include<iostream>
#include<sstream>
#include<string>
#include<vector>
#include<list>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<algorithm>
#pragma warning(disable:4996)
#include<cstdio>
#include<cstdlib>
using std::cin;
using std::cout;
using std::endl;
using std::stringstream;
using std::string;
using std::vector;
using std::list;
using std::pair;
using std::set;
using std::multiset;
using std::map;
using std::multimap;
using std::stack;
using std::queue;
using std::priority_queue;
int main()
{
	//freopen("input.txt", "r", stdin);  
	//freopen("output.txt", "w", stdout);  
	long long n;
	while (cin >> n&&n)
	{
		long long cost = 0;
		vector<long long>wine(n);
		for (int i = 0; i < n; i++)
		{
			cin >> wine[i];
		}
		for (long long i = 0; i < n; i++)
		{
			if (wine[i] > 0)
			{
				for (long long j = i + 1; j < n&&wine[i]; j++)
				{
					if (wine[j] < 0)
					{
						auto bargain = std::min(wine[i], -wine[j]);
						cost+=(j-i)*bargain;
						wine[i] -= bargain;
						wine[j] += bargain;
					}
				}
			}
			else if (wine[i] == 0) {}
			else
			{
				for (long long j = i + 1; j < n&&wine[i]; j++)
				{
					if (wine[j] > 0)
					{
						auto bargain = std::min(-wine[i], wine[j]);
						cost += (j - i)*bargain;
						wine[i] += bargain;
						wine[j] -= bargain;					
					}
				}
			}
		}
		cout << cost << endl;
	}
	return 0;
}