It might, but if you're going to evaluate all possibilities, who cares? As in, if you are worried about a scenario such as the following, where the 10 gets bagged "solo" despite there being a -5 farther down the pipeline:      ( [ 9 ], [ 10, -5], [ 11 ] ) Then later on you will inevitably evaluate a scenario where the -5 is inserted earlier.      ( [ 9, -5, 10 ], [11] ) So, taking the "brute force" approach, you might lose points for style, but you get the job done, no?

Has anyone ever pointed out to a grocery checker that the bagging problem was NP-complete? The result might be similar to explaining that dogs can solve quadratic equations (i.e. capturing a frisbee in a parabolic arc while in linear motion).