The Clumsy Coupon Collector
摘要
We describe a generalisation of the classical coupon collector problem, in which at each time step a collector either receives a new copy of a randomly chosen coupon, or looses all their previously collected copies of that coupon. We consider the amount of time it takes this clumsy coupon collector to obtain the full set of n coupons. We conjecture that the mean and variance of the clumsy coupon collector time are exponential in n, but that a standardised clumsy coupon collector time converges to a Gumbel distribution, as is the case for the classical coupon collector.