If you were under age 24 at the end of the year, and your parents provided more than half of your total support, they may still be able to claim you as a dependent. Support includes housing/rent, utilities, meals, education, etc. If that is not the case, you would claim yourself as the dependent.
However, if you were 24 or older at December 31, you would have had to have made less than $4,200 in order for your parents to claim you as a qualifying relative. If you made more than $4,200 in 2019, they may no longer claim you.
Education is considered a temporary absence and does not affect the time spent in the home. So, if you moved in with them following your graduation, you are considered to have lived in their home for the entire year.