Enough is sometimes used after nouns. The reversal is a form of emphasis. It is a little old fashioned and literary, and is acceptable in formal writing. Example - "Columbia College Today: At the same time, the space demands of teaching and research are ever growing, ever expanding. That Columbia does not have enough space today is problem enough"
The noun can be in a singular or plural form.
Don’t ask questions – there’ll be time enough for that later.
He had reason enough to be angry
I was fool enough to trust her
A gâteau weighing 2 Kg should be cake enough for anybody.
Had we but world enough and time,
This coyness, lady, were no crime.
We would sit down, and think which way
To walk, and pass our long love’s day.
Andrew Marvell (1621-1678) To His Coy Mistress
But are these reasons enough to justify their continued use?
Brazil has problems enough of its own
Enough (Macmillan Dictionary)