How do you create pseudo random numbers sequentially in c/c++?

srand(time(NULL));
for (it=hand.begin(); it < hand.end(); it++)
    (*it) = rand() % 13 + 1;

This code does not work to create many random numbers at a time. Is there a way to do it that isn't as开发者_如何学C complex as Mersennes and isn't operating system dependent?

PRNGs don't create many PRNs at once. Each output is dependent on the previous output, PRNGs are highly stateful.

Try:

srand(time(NULL)); // once at the start of the program

for( int i = 0; i < N; ++i )
    r[i] = rand();

Even APIs that return an entire block of output in a single function call, have just moved that loop inside the function.

Call srand just once, at the start of your program. Then call rand() (not srand(rand())) to generate each random number.

Boost.Random has lots of good random number generators which are easy to use.

George Marsaglia posted a Multiply With Carry PRNG some time ago in sci.math.

I cannot say how good it is or how well it behaves, but you might want to give it a try.

It should be OS and platform independent.

"please make sure you answer the question" OK

for (int i=n1; i < n2; ++i)
  { 
  int k; 
  do k = rand(); while (i !=k); 
  // k is a sequential pseudo random number
  }

There may be issues with efficiency...