In c++, what happends when i add 1 to the rand_max then take rand() deivded by (rand_max+1)? if my purpose is to take out a random number within 0=< and =< 1?

Explanation:

rand() function is used to generate random integers between the range 0 to RAND_MAX.So if we divide the the rand() function by RAND_MAX the value returned will be 0.

You cannot do RAND_MAX + 1 the compiler will give error integer overflown.

To generate an integer with a range.You have to do like this:

srand(time(0));

int a=-1*(rand() % (0 - 5245621) +1);

cout <<a;

This piece of code will return an integer within the range 0 to -5245622.