861. Score After Flipping Matrix - Explanation

class Solution:
    def matrixScore(self, grid: List[List[int]]) -> int:
        ROWS, COLS = len(grid), len(grid[0])

        for r in range(ROWS):
            if grid[r][0] == 0:
                for c in range(COLS):
                    grid[r][c] ^= 1

        for c in range(COLS):
            one_cnt = sum(grid[r][c] for r in range(ROWS))
            if one_cnt < ROWS - one_cnt:
                for r in range(ROWS):
                    grid[r][c] ^= 1

        res = 0
        for r in range(ROWS):
            for c in range(COLS):
                res += grid[r][c] << (COLS - c - 1)

        return res

class Solution:
    def matrixScore(self, grid: List[List[int]]) -> int:
        ROWS, COLS = len(grid), len(grid[0])
        res = ROWS * (1 << (COLS - 1))

        for c in range(1, COLS):
            cnt = 0
            for r in range(ROWS):
                if grid[r][c] != grid[r][0]:
                    cnt += 1

            cnt = max(cnt, ROWS - cnt)
            res += cnt * (1 << (COLS - c - 1))

        return res