Set Matrix Zeroes

Problem statement

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?

My solution

/**
 * @param {number[][]} matrix
 * @return {void} Do not return anything, modify matrix in-place instead.
 */
var setZeroes = function(matrix) {
    for (let i = 0; i < matrix.length; i++) {
        for (let j = 0; j < matrix[i].length; j++) {
            if (matrix[i][j] === 0) {
                mark(i, j)
            }
        }
    }
    
    for (let i = 0; i < matrix.length; i++) {
        for (let j = 0; j < matrix[i].length; j++) {
            if (matrix[i][j] === "#") {
                matrix[i][j] = 0
            }
        }
    }
    
    
    
    function mark(row, col) {
        for (let i = 0; i < matrix[0].length; i++) {
            if (matrix[row][i] !== 0) {
                matrix[row][i] = "#"
            }
        }
        
        for (let i = 0; i < matrix.length; i++) {
            if (matrix[i][col] !== 0) {
                matrix[i][col] = "#"
            }
        }
    }

    // console.log(matrix)
};