Splitting an order across sessions

A parent order is cut into $n$ child orders of sizes $q_1, \dots, q_n$ (in thousands of shares) that must be executed in this order over $D$ trading sessions. Each session takes a consecutive block of child orders. Choose the blocks to minimise the largest session total. For $q = [4, 8, 3, 6, 5, 2]$ and $D = 3$, what is the answer, and how fast can you compute it in general?