Random numbers from -20 to 20

Question

#define LEFT -20
#define RIGHT 20
if we do some_variable=rand()%RIGHT+LEFT - we get random numbers from 0 to -20;
but if i try to do soem_variable=rand%(2*RIGHT)+LEFT - i still dont get numbers from -20 to 20 interval.

Pretty dumb question but i really forgot how to do this

Answer 1

rand()%(Right- Left +1)+Left

Answer 2

Thank you!