[LeetCode] HashTable/ 73. Set Matrix Zeroes

from collections import defaultdict

class Solution:
    def setZeroes(self, matrix: List[List[int]]) -> None:
        """
        Do not return anything, modify matrix in-place instead.
        """
        n = len(matrix)
        m = len(matrix[0])
        
        rows = defaultdict(int)
        cols = defaultdict(int)
        
        for i in range(n):
            for j in range(m):
                if (matrix[i][j] == 0):
                    rows[i] = 1
                    cols[j] = 1
        
        for i in range(n):
            for j in range(m):
                if (rows[i] == 1 or cols[j] == 1):
                    matrix[i][j] = 0
        return matrix