This may be overkill, but the cantor function with $S=$ the middle-thirds cantor set will work:
2 properties of this function are: $S^\circ = \emptyset$ and $f(S)=[0,1]$
This may be overkill, but the cantor function with $S=$ the middle-thirds cantor set will work:
2 properties of this function are: $S^\circ = \emptyset$ and $f(S)=[0,1]$