题目描述：
中文：
给定一个 m x n 的矩阵，如果一个元素为 0，则将其所在行和列的所有元素都设为 0。请使用原地算法。
英文：
Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in-place.
class Solution(object):
def setZeroes(self, matrix):
"""
:type matrix: List[List[int]]
:rtype: None Do not return anything, modify matrix in-place instead.
"""
rownum = len(matrix)
colnum = len(matrix[0])
row = [False for i in range(rownum)]
col = [False for i in range(colnum)]
for i in range(rownum):
for j in range(colnum):
if matrix[i][j] == 0:
row[i] = True
col[j] = True
for i in range(rownum):
for j in range(colnum):
if row[i] or col[j]:
matrix[i][j] = 0
题目来源：力扣
