Method isColumnSafe

C++/Sudoku-Solver.cpp:22–30

to check whether num is valid in that column

    
    // to check whether num is valid in that column
    bool isColumnSafe(vector<vector<char>>& board, int col , char  num)
    {
         for(int row = 0; row<9; row++)
        {
            if(board[row][col] == num)
                return true;
        }
        return false;
    }
    
    // to check whether num is valid in that 3*3 matrix grid 
    bool isBoxSafe(vector<vector<char>>& board, int row1, int col1 , char  num)