how to generate random number from 0.5 to 1.0

Question

How to Generate the random number from 0.5 to 1.0 .

Answer 1

You can try:

float RandomBetween(float smallNumber, float bigNumber)
{
    float diff = bigNumber - smallNumber;
    return (((float) rand() / RAND_MAX) * diff) + smallNumber;
}

Answer 2

You should be able to use something like:

double x = ((double)rand()) / ((double)RAND_MAX) / 2.0 + 0.5;

The division by RAND_MAX gives you a value from 0 to 1, dividing that by two drops the range to 0 to 0.5, then adding 0.5 gives you 0.5 to 1. (inclusive at the low end and exclusive at the top end).