I had that happen framing some condos a while back, had about an inch of water everywhere. All you can do is take the claw of your hammer and start poking holes in the floor. Make sure the building is dried out and moisture tested before adding any finished flooring. Patching the holes could be an issue but its worth it to get the floor to drain in my opinion, minimize the swelling.
I don't get the people saying if you frame the floor properly it will drain, makes no sense. I framed about a thousand buildings, every one of them puddled water on the floor to a certain extent. Do you guys frame your houses crooked and slope the floor so it drains?