两种方法:
第一种:先对二维列表的每一列进行排序,然后对每一列的数据进行逐个比较,找出最大值。
class Solution:
    def matrixSum(self, nums: list[list[int]]) -> int:
        result=0
        m=len(nums)
        n=len(nums[0])
        for i in range(m):
            nums[i].sort()
        for j in range(n):
            max_1 = 0
            for i in range(m):
                max_1 = max(max_1,nums[i][j])
            result+=max_1
        return result
nums = Solution()
print(nums.matrixSum([[7,2,1],[6,4,2],[6,5,3],[3,2,1]]))第二种:先对二维列表每行进行排序,后利用python的内置函数zip进行计算(时间复杂度底)
zip函数详细用法请看菜鸟教程:Python zip() 函数 | 菜鸟教程 (runoob.com)
class Solution:
    def matrixSum(self, nums: List[List[int]]) -> int:
        for row in nums:
            row.sort()
        result = 0
        for col in zip(*nums):
            result += max(col)
        return result
nums = Solution()
print(nums.matrixSum([[7,2,1],[6,4,2],[6,5,3],[3,2,1]]))