Return Elements Greater Than the Overall Average

Question

This question asks the candidate to write a function that returns all elements from a given list that are greater than the overall average of the list.

Codemia · Accepted Answer

To solve the problem, I will first calculate the average of the elements in the list. Then, I will filter the list to return only those elements that are greater than this average. This two-step approach ensures clarity and simplicity in the implementation.

Here’s a simple algorithm to achieve this:
1. Calculate the sum of all elements in the list.
2. Divide the sum by the number of elements to get the average.
3. Use a list comprehension to gather all elements that are greater than the average.

Here’s the Python code implementing this logic:
```python
def elements_greater_than_average(nums):
    if not nums:
        return []  # Handle empty list case
    average = sum(nums) / len(nums)
    return [num for num in nums if num > average]
```

The time complexity of this solution is O(n), where n is the number of elements in the list. This is because we need to iterate through the list to calculate the sum and then again to filter the elements. The space complexity is O(k), where k is the number of elements greater than the average, as we are storing those elements in a new list.

It is important to consider edge cases such as an empty list, which I have handled in the code by returning an empty list. Additionally, if all elements are equal, the returned list would also be empty since no element would be greater than the average.

Interviewers are looking for a clear explanation of the thought process, the ability to write clean and efficient code, and consideration of edge cases. They also value the candidate's ability to communicate their reasoning and approach throughout the problem-solving process.

Return Elements Greater Than the Overall Average

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