Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place.

Follow up:

Did you use extra space?
A straight forward 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 {
public:
    void setZeroes(vector<vector<int> > &matrix) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int m = matrix.size();
        if (m == 0) return;
        int n = matrix[0].size();
        if (n == 0) return;
        
        bool isFirstRowZero = false;
        bool isFirstColZero = false;
        for (int i = 0; i < n; ++i)
        {
            if (matrix[0][i] == 0)
            {
                isFirstRowZero = true;
                break;
            }
        }
        
        for (int i = 0; i < m; ++i)
        {
            if (matrix[i][0] == 0)
            {
                isFirstColZero = true;
                break;
            }
        }
        
        for (int i = 1; i < m; ++i)
        {
            for (int j = 1; j < n; ++j)
            {
                if (matrix[i][j] == 0)
                {
                    matrix[0][j] = 0;
                    matrix[i][0] = 0;
                }
            }
        }
        
        for (int i = 1; i < m; ++i)
        {
            for (int j = 1; j < n; ++j)
            {
                if (matrix[0][j] == 0 || matrix[i][0] == 0)
                    matrix[i][j] = 0;
            }
        }
        
        if (isFirstRowZero)
        {
            for (int i = 0; i < n; ++i)
                matrix[0][i] = 0;
        }
        if (isFirstColZero)
        {
            for (int i = 0; i < m; ++i)
                matrix[i][0] = 0;
        }
    }
};