Display categories of all posts within search result

When the user performs a search on my website, all results are displayed based on relevance. Therefore, posts from different categories appear on the list.

I already have in place a “result counter” which says:

“We have found (# of results) results”

What I want to add is the categories of all posts within the search result. The message would go:

“We have found (# of results) results” in the Category 1, Category 2 and Category 3″

Anyone can point me in the right direction?

Thank you so much for any future insights