leetcode 43: Set Matrix Zeroes

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

uncompleted

class Solution {
public:
    void setZeroes(vector<vector<int> > &matrix) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        
        if( matrix.size() == 0 ) return;
        
        size_t row = matrix.size();
        size_t col = matrix[0].size();
        
        bool row_flag = false, col_flag = false;
        
        for( int i=0; i<row; i++) {
            if( matrix[i][0] == 0 ) {
                row_flag = true;
            }
        }
        
        
        for( int j=0; j<col; j++) {
            if( matrix[0][j] == 0 ) {
                col_flag = true;
            }
        }
        
        
        for( int i=1; i< row; i++) {
            for ( int j=1; j< col; j++) {
                if( matrix[i][j] == 0 ) {
                    matrix[0][j] = 0;
                    matrix[i][0] = 0;
                }
            }
        }
        
        for( int i=0; i<matrix.size(); i++) {
            if(matrix[i][0] == 0) {
                for( int j=1; j<matrix[0].size(); j++){
                    matrix[i][j] = 0;
                }
            } else if(row_flag) {
                matrix[i][0] = 0;
            }
        }
        
        for( int j=0; j<matrix[0].size(); j++) {
            if(matrix[0][j] == 0) {
                for( int i=1; i<matrix.size(); i++){
                    matrix[i][j] = 0;
                }
            } else if(col_flag) {
                matrix[0][j] = 0;
            }
        }
    }
};