Damien WOODS, Matthew PATITZ, Scott SUMMERS, David DOTY and Jack H. LUTZ
Abstract. We investigate methods for exploiting nondeterminism inherent within the Tile Assembly Model in order to generate uniform random numbers. Namely, given an integer range (0,...,n-1), we exhibit methods for randomly selecting a number within that range. We present three constructions exhibiting a trade-off between space requirements and closeness to uniformity. The first selector selects a random number with probability Theta(1/n) using O(log^2 n) tiles. The second selector takes a user-specified parameter that guarantees the probabilities are arbitrarily close to uniform, at the cost of additional space. The third selector selects a random number with probability exactly 1/n, and uses no more space than the first selector with high probability, but uses potentially unbounded space.