We have to paint n boards of length [A1, A2, ..., An]. There are k painters available and each takes 1 unit time to paint 1 unit of board. The problem is to find the minimum time to get this job done under the constraints that any painter will only paint continuous sections of boards, say board {2, 3, 4} or only board {1} or nothing but not board {2, 4, 5}.
When k = 2 and A = [10, 10, 10, 10], the output should be 20.
When k = 2 and A = [10, 20, 30, 40], the output should be 60 since we can divide first 3 boards for one painter and the last board for second painter.