class Solution:
def setZeroes(self, matrix: List[List[int]]) -> None:
"""
Do not return anything, modify matrix in-place instead.
"""
m, n = len(matrix), len(matrix[0])
col0 = 1 #第0列标志位
for i in range(m):
if matrix[i][0] == 0:
col0 = 0
for j in range(1, n):
if matrix[i][j] == 0:
matrix[i][0] = matrix[0][j] = 0
for i in range(m-1, -1, -1):
for j in range(n-1, 0, -1):
if matrix[i][0] == 0 or matrix[0][j] == 0:
matrix[i][j] = 0
if not col0: #特殊处理第0列
matrix[i][0] = 0