C++ generating random numbers

Question

My output is 20 random 1\'s, not between 10 and 1, can anyone explain why this is happening?

#include  
#include  
#include <         


        

Answer 1

Because, on your platform, RAND_MAX == INT_MAX.

The expression range*rand() can never take on a value greater than INT_MAX. If the mathematical expression is greater than INT_MAX, then integer overflow reduces it to a number between INT_MIN and INT_MAX. Dividing that by RAND_MAX will always yield zero.

Try this expression:

random_integer = lowest+int(range*(rand()/(RAND_MAX + 1.0)))