There are heights for bars from a bar-chart provided. Find the maximum area of a contiguous rectangle bounded by the bar chart in a streaming manner where the bars appear to the right along the x-axis.

public void getMaxRectangleByStream(List<int> A, List<int> sums, int current)

{

   for (int i = 0; i < sums.size(); i++)

   {

        for (j = i; j < sums.size(); j++)

        {

if (A[j] <= current && sums[j] >= A[j] * (sums.size()-j))

        {

              sums[j] += A[j];

        }

                break;

        }

   }

   int sum = current;

   for (int j = sums.size() - 1; j >= 0; j--)

   {

       if (A[j] >= current)

       {

          sum += current;

       }

       else

       {

         break;

       }

   }

   sums.Add(sum);

}

class Solution {

    public int solution(List<int> A) {

        var sums = new List<int>();

        for (int i = 0; i < A.length(); i++)

        {

getMaxRectangleByStream(A, sums, A[i]);

        }

        return sums.stream().max();

}

            

A:            4, 6, 2, 4, 12, 7, 4, 2, 2, 2

sums:    8, 6, 20, 16, 12, 14, 16, 20, 20, 20