Maximum sum after K negations

maximum_sum_after_k_negations.py

"""
https://scammingthecodinginterview.com
Week 3: Greedy
Problem: 3
"""

class Solution(object):

    def solve(self, a, k):

        a.sort()
        index = 0

        for num in a:
            if num < 0 and index < k:
                a[index] = -a[index]
                index += 1

        index = k - index

        s = sum(a)

        if index > 0:
            index = index % 2
            if index:
                m = min(a)
                s -= 2 * m

        return s


if __name__ == "__main__":

    a = [2, -3, -1, 5, -4]
    k = 2
    ans = Solution().solve(a, k)

    print(ans)