MatrixZeros.py

'''
# https://leetcode.com/problems/set-matrix-zeroes/
Given an m x n integer matrix matrix, if an element is 0, set its entire row and column to 0's.

You must do it in place.

 

Example 1:


Input: matrix = [[1,1,1],[1,0,1],[1,1,1]]
Output: [[1,0,1],[0,0,0],[1,0,1]]
Example 2:


Input: matrix = [[0,1,2,0],[3,4,5,2],[1,3,1,5]]
Output: [[0,0,0,0],[0,4,5,0],[0,3,1,0]]
 

Constraints:

m == matrix.length
n == matrix[0].length
1 <= m, n <= 200
-231 <= matrix[i][j] <= 231 - 1
 

Follow up:

A straightforward solution using O(mn) space is probably a bad idea.
A simple improvement uses O(m + n) space, but still not the best solution.
Could you devise a constant space solution?
'''
class Solution:
    def setZeroes(self, matrix: list[list[int]]) -> None:
        """
        Do not return anything, modify matrix in-place instead.
        """
        row_q = [ ]
        col_q = [ ]
        
        m = len(matrix)
        n = len(matrix[0])
        
        for r in range(m):
            for c in range(n):
                if matrix[r][c] == 0:
                    row_q.append(r)
                    col_q.append(c)
                    
        for r in row_q:
            for c in range(n):
                matrix[r][c] = 0
        
        for c in col_q:
            for r in range(m):
                matrix[r][c] = 0
                
if __name__ == "__main__":
    s = Solution()
    matrix = [[1,1,1],[1,0,1],[1,1,1]]
    s.setZeroes(matrix)
    print(matrix)
    
    matrix = [[0,1,2,0],[3,4,5,2],[1,3,1,5]]
    s.setZeroes(matrix)
    print(matrix)