Write a method to generate a random number between 1 and 7?

Question

Generate random number form 1 - 100 with probability of 1/100.You are not allowed to used rand() function.
Any simple way of achieving above with using any complex implementation of random number generators algorithm.

Answer 1

int i;
do
{
  i = 5 * (rand5() - 1) + rand5();  // i is now uniformly random between 1 and 25
} while(i > 21);
// i is now uniformly random between 1 and 21
return i % 7 + 1;  // result is now uniformly random between 1 and 7