Maximizing profit for given stock quotes

Question

I was asked this question while interviewing for a startup and saw this again in the recent contest at

Code Sprint:systems

**The question :

You are

Answer 1

private static int MaxProfit(int[] A)
        {
            if (A.Length == 0)
                return 0;
            Stack repositoryStack = new Stack();
            int maxProfit = 0;
            int tempProfit;
            for (int i = 0; i < A.Length; i++)
            {
                if (repositoryStack.Count == 0)
                {
                    repositoryStack.Push(i);
                    continue;
                }
                while (repositoryStack.Count != 0 && A[i] < A[repositoryStack.Peek()])
                {
                    repositoryStack.Pop();
                }
                if (repositoryStack.Count != 0 && A[i] > A[repositoryStack.Peek()])
                {
                    tempProfit = A[i] - A[repositoryStack.Peek()];
                    if (tempProfit > maxProfit)
                        maxProfit = tempProfit;
                }
                if(repositoryStack.Count == 0)
                    repositoryStack.Push(i);
            }
            return maxProfit;
        }