Code
#include <bits/stdc++.h>
using namespace std;

class Solution {
public:
     // Function to set entire row and column to 0 if an element in the matrix is 0
    void setZeroes(vector<vector<int>>& matrix) {
        // Get number of rows
        int m = matrix.size();
        // Get number of columns
        int n = matrix[0].size();

        // Traverse each cell of the matrix
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                // If current cell is zero
                if (matrix[i][j] == 0) {
                    // Mark all elements in this row as -1 (except existing zeros)
                    for (int col = 0; col < n; col++) {
                        if (matrix[i][col] != 0)
                            matrix[i][col] = -1;
                    }
                    // Mark all elements in this column as -1 (except existing zeros)
                    for (int row = 0; row < m; row++) {
                        if (matrix[row][j] != 0)
                            matrix[row][j] = -1;
                    }
                }
            }
        }

        // Second pass: replace all -1 markers with 0
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                if (matrix[i][j] == -1)
                    matrix[i][j] = 0;
            }
        }
    }
};

int main() {
    // Example matrix
    vector<vector<int>> matrix = {{1,1,1},{1,0,1},{1,1,1}};
    
    // Create Solution object
    Solution sol;
    // Call function to modify matrix
    sol.setZeroes(matrix);
    
    // Print final matrix
    for (auto row : matrix) {
        for (auto val : row) {
            cout << val << " ";
        }
        cout << endl;
    }
    return 0;
}