MediumProbabilitypr-030

Coupon Collector Expected Count

Problem

Expected number of draws to collect all n distinct coupons: n * H_n, where H_n = 1 + 1/2 + ... + 1/n.

Return 0.0 for n <= 0.

Hint

After k distinct coupons, the expected wait for a new one is n / (n - k).

case 1

in: [1]

expected: 1

case 2

in: [2]

expected: 3

case 3

in: [3]

expected: 5.5

case 4

in: [10]

expected: 29.289682539682538

case 5

in: [52]

expected: 235.97828543626724

Starter codePython

def coupon_collector_expected(n):
    # Your code here
    pass

5 test cases · run your code against them in the editor