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# 1975. Maximum Matrix Sum
"""
you are given an 'n x n' integer 'matrix'. you can do the following operation
any number of times: choose any two adjacent elements of 'matrix' and
multiply each of them by -1. two elements are considered adjacent if and only
if they share a border. your goal is to maximise the summation of the
matrix's elements. return maximum sum of the matrix's elements using the
afforementioned operation.
"""
class Solution(object):
def maxMatrixSum(self, matrix):
"""
:type matrix: List[List[int]]
:rtype: int
"""
ans, mult, val = 0, 0, float("inf")
for i in range(len(matrix)):
for j in range(len(matrix)):
ans += abs(matrix[i][j])
val = min(val, abs(matrix[i][j]))
if matrix[i][j] < 0:
mult ^= 1
return ans - 2 * mult * val
if __name__ == "__main__":
obj = Solution()
print(obj.maxMatrixSum(matrix=[[1, -1], [-1, 1]]))
print(obj.maxMatrixSum(matrix=[[1, 2, 3], [-1, -2, -3], [1, 2, 3]]))
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