algoadvance

  1. Input Format: What is the format of the input? Is it always a list of integers?
  2. Constraints: What are the possible sizes of the input list? Are negative and duplicate values allowed in the list?
  3. Output Format: Do you need the count of elements directly, or are there any specific restrictions/requirements for the output format?

Strategy

To solve the problem of counting elements that have both a strictly smaller and a strictly greater element in the list, we can follow these steps:

  1. Sort the List: Sorting the list will help us identify the smallest and largest elements easily.
  2. Minimum and Maximum Elements: Identify the smallest and largest elements in the sorted list.
  3. Count Valid Elements: Iterate through each element of the list and check if it is neither the smallest nor the largest. If true, then it satisfies the condition of having both a strictly smaller and a strictly greater element.

Code

Here’s an implementation of the described strategy:

def count_elements(nums):
    if len(nums) < 3:
        # If there are less than 3 elements, there can't be an element with both
        # a strictly smaller and a strictly greater element.
        return 0

    # Sort the list to easily get the minimum and maximum values.
    sorted_nums = sorted(nums)
    
    min_val = sorted_nums[0]
    max_val = sorted_nums[-1]
    
    count = 0
    for num in nums:
        if num > min_val and num < max_val:
            count += 1
    
    return count

# Example usage:
nums = [11, 7, 2, 15]
print(count_elements(nums))  # Output: 2

nums = [-3, 3, 3, 90, -3]
print(count_elements(nums))  # Output: 1

Time Complexity

Thus, the overall time complexity of the solution is (O(n \log n)).

If there are no further clarifications needed, this should suffice as an efficient and comprehensive solution to the problem.

Try our interview co-pilot at AlgoAdvance.com