I would avoid the censored example, simply because it feels awkward. Unless that character genuinely dislikes swearing or has some other motive for censoring him/herself, it will come off as incredibly unnatural. Few people actually talk like that.
Personally, I typically go with the bold example. As long as it fits the scene and mood and it's not too overdone, I believe that, to a degree, swearing in YA is deemed acceptable. After all, let's face it, the readers are going to be at that level of language themselves. If you placed such words in every other sentence, it might get a little extreme, but as long as it's called for, I wouldn't worry in it. Of course, cutting the word might help inject a moment of comedy into your scene, but if used multiple times for no reason, it will just seem unnatural.