Average Value of Even Numbers That Are Divisible by Three — LeetCode 2455 Python Solution

The problem

Given an integer array nums of positive integers, return the average value of all even integers that are divisible by 3. Note that the average of n elements is the sum of the n elements divided by n and rounded down to the nearest integer.

Example

Input

nums = [1,3,6,10,12,15]

Output

9

Explanation

6 and 12 are even numbers that are divisible by 3. (6 + 12) / 2 = 9.

Python solution

class Solution:
    def averageValue(self, nums: List[int]) -> int:
        s = n = 0
        for x in nums:
            if x % 6 == 0:
                s += x
                n += 1
        return 0 if n == 0 else s // n

Complexity

Pattern: Math and Number Theory

Find the closed form, the invariant, or the modular identity — and skip the loop entirely. LeetCode 2455. Average Value of Even Numbers That Are Divisible by Three is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Math.

The math and number theory guide has the Python template for the pattern and the 485 LeetCode problems that use it.

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