easy

使用两个数组shuax,shuay分别记录为0的i和j下标

然后两个for循环分别对行，列刷一次就可以了，虽然这样很浪费内存并且复杂度有点高，但能过就行。

class Solution:
    def setZeroes(self, matrix: List[List[int]]) -> None:
        """
        Do not return anything, modify matrix in-place instead.
        """
        m=len(matrix)
        n=len(matrix[0])
        shuax=[]
        shuay=[]
        for i in range(m):
            for j in range(n):
                if matrix[i][j]==0:
                    shuax.append(i)
                    shuay.append(j)
        for i in range(m):
            if i in shuax:
                for j in range(n):
                    matrix[i][j]=0
        for j in range(n):
            if j in shuay:
                for i in range(m):
                    matrix[i][j]=0