Make K-Subarray Sums Equal — LeetCode 2607 Python Solution

The problem

You are given a 0-indexed integer array arr and an integer k. The array arr is circular.

Example

Input

arr = [1,4,1,3], k = 2

Output

1

Explanation

we can do one operation on index 1 to make its value equal to 3.

Python solution

class Solution:
    def makeSubKSumEqual(self, arr: List[int], k: int) -> int:
        n = len(arr)
        g = gcd(n, k)
        ans = 0
        for i in range(g):
            t = sorted(arr[i:n:g])
            mid = t[len(t) >> 1]
            ans += sum(abs(x - mid) for x in t)
        return ans

Complexity

Pattern: Greedy

Take the locally best option every time — when you can prove that never costs you later. LeetCode 2607. Make K-Subarray Sums Equal is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Greedy.

The greedy guide has the Python template for the pattern and the 346 LeetCode problems that use it.

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