* A rand5() function gives uniform integer results between 1 and 5. How can you use it to build a rand7() function?
* Build a function rand(x, y, r) that returns a uniformly random point in the circle given by the (x,y) center and the r radius.
* What’s the expected number of times line x is executed if p is a uniform random permutation of numbers 1 .. n.

==code(python) |
 min = p[0]
 for x in p:
   if min > x:
     min = x
==

* Build an algorithm that returns uniform random permutations.
* Given a stream of integers build an algorithm that returns a uniform random sample of size k using O(k) memory.
* (Coupon collector’s problem) Suppose a kid wants to collect all the cartoon characters in a kinder surprise series. Given that there are n different characters in total and they are distributed uniformly random