# Coding Interviews: Arrays and Strings

Given an integer array nums, return *an array* answer *such that* answer[i] *is equal to the product of all the elements of* nums *except* nums[i].

The product of any prefix or suffix of nums is **guaranteed** to fit in a **32-bit** integer.

You must write an algorithm that runs in O(n) time and without using the division operation.

You have observations of n + m **6-sided** dice rolls with each face numbered from 1 to 6. n of the observations went missing, and you only have the observations of m rolls. Fortunately, you have also calculated the **average value** of the n + m rolls.

You are given an integer array rolls of length m where rolls[i] is the value of the ith observation. You are also given the two integers mean and n.

Return *an array of length *n* containing the missing observations such that the ***average value ***of the *n + m* rolls is ***exactly*** *mean. If there are multiple valid answers, return *any of them*. If no such array exists, return *an empty array*.

The **average value** of a set of k numbers is the sum of the numbers divided by k.

Note that mean is an integer, so the sum of the n + m rolls should be divisible by n + m.