There is a slight difference between the literal wording of the close reason:
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
and the way it is used on this stack and others. The general rule is: a question is a duplicate of another if it naturally gets the same answers. In other words, the second sentence of the message is more significant than the first. On other stacks this is because the point is to guide people to the right answer, and closing with a link to a page which answers their question achieves that goal.
This stack is different, because it's about having fun answering rather than resolving people's uncertainties. However, a similar principle applies. If we already have a page of answers which just need a tiny tweak, what's the point of copying them all across? Maybe it lets people get double points for their answers, but the attention drawn by the closed question pointing at the older one usually gives the better answers a small bump anyway.
In this particular case, your question is closer to the existing one than many which get closed as duplicates on the grounds that existing answers just need a small tweak to solve them. (See e.g. Partition of array).
I should note one exception: when a very general problem has been asked, a more specific instance might be worth keeping open if there is a good reason to expect that the additional structure will allow solutions which aren't applicable to the general problem but are better than the solutions to the general problem.