Product of the Last K Numbers

Medium · Arrays & Strings · about 20 minutes

Asked at Google, Amazon, ByteDance, Microsoft.

Design a structure that receives integers one at a time and can report the product of the most recent ones.

• ProductOfNumbers() starts with nothing stored.
• add(num) records a new value (0 ≤ num ≤ 100).
• getProduct(k) returns the product of the k values added most recently. At least k values have been

added, and the product fits in a 32-bit integer.