The Crowd Splitter

An easy Python interview practice problem on DataDriven. Write the Python and run it against test cases, with instant feedback.

Domain
Python
Difficulty
easy
Seniority
L4
Asked in
Alcon

Problem

Given a list of integers where one value appears strictly more than half the time, return its value. The median equals that dominant value.

The middle holds even with a dominant outlier.

Example 1

Input:

nums = [1,2,2,2,3]

Output:

2

Example 2

Input:

nums = [7,7,7,7,1,2,3]

Output:

7

Worked solution and explanation

Why this problem exists in real interviews

This tests whether a candidate recognizes that a majority element is always the median of the list. It probes algorithmic insight: if one value dominates more than half the positions, it must occupy the center after sorting.

Break down the requirements

Step 1: Sort the list

With a majority element guaranteed, the median position is always occupied by that element.

Step 2: Return the middle element

Index len(nums) // 2 gives the median. The majority element is guaranteed to be there.

The solution

Sort and pick the median
def find_median(nums: list) -> int:
    sorted_nums = sorted(nums)
    median = sorted_nums[len(sorted_nums) // 2]
    return median

Common follow-up questions