请教各位前辈指点一下算法的问题

Question

int rowNumber = 10, colNumber = 10;
            int[,]a=new int [rowNumber,colNumber];
            double cellsize=1;
            int lineID = 1,col,j,row;
            double x1 = 1, y1 = 2;
            double x2 = 8, y2 = 6;
            double k = (y2-y1)/(x2-x1),b = y1-x1*k; 
            int col1=(int)(x1/cellsize),col2=(int)(x2/cellsize);
            int row1=(int)(y1/cellsize),row2=(int)(y2/cellsize);
            if (k > 1 || k < -1)
            { 
              for (col= col1; col < col2;col++ )
               {
                       double y0 =col*k+b;
                       
                       double x = col+1;
                       double y = x*k+b;
                       double p = Math.Ceiling(y-y0);
                       for(j=0;j<p;j++)
                       {
                          int yz = (int)(y0);
                           a[yz, col] = lineID;
                           Console.WriteLine("a[{0},{1}]={2}", yz,col, a[yz, col]);                                  y0++;
                       }
                       
                
               }
              
            }
              else
              {
                      for (row = row1; row < row2;row++ )
               {
                       double x0 =(row-b)/k;
                       
                       double y = row+1;
                       double x = (y-b)/k;
                       double p = Math.Ceiling(x - x0);
                        
                       for(j=0;j<p;j++)
                       {
                           int xz = (int)(x0);
                           a[row, xz] = lineID;
                           Console.WriteLine("a[{0},{1}]={2}", row,xz, a[row,xz]);
 ;
                           x0++;
       
                                
                       }
                       
                
               }
              
              }程序定义了一个10乘10的数组。。想要看看从点（1，2）到点（8，6）形成的线段穿过了哪些“格子”。。然后给穿过的这些格子赋值lineID。每次运行出来结果都不对。好像差了几个格子。请各位前辈指教一下很着急很着急！！！非常感谢！！！

Answer 1

最简单的平面几何直线方程式，两点式...查书去吧，中学怎么学的啊....NET门槛真这么低吗...唉...

Answer 2

直改了else子句中的代码，其他自己改吧
        public void Func1()
        {
            int rowNumber = 10, colNumber = 10;
            int[,] a = new int[rowNumber, colNumber];
            double cellsize = 1;
            int lineID = 1, col, j, row;
            double x1 = 1, y1 = 2;
            double x2 = 8, y2 = 6;
            double k = (y2 - y1) / (x2 - x1), b = y1 - x1 * k;
            int col1 = (int)(x1 / cellsize), col2 = (int)(x2 / cellsize);
            int row1 = (int)(y1 / cellsize), row2 = (int)(y2 / cellsize);
            if (k > 1 || k < -1)
            {
                for (col = col1; col < col2; col++)
                {
                    double y0 = col * k + b;                    double x = col + 1;
                    double y = x * k + b;
                    double p = Math.Ceiling(y - y0);
                    for (j = 0; j < p; j++)
                    {
                        int yz = (int)(y0);
                        a[yz, col] = lineID;
                        Console.WriteLine("a[{0},{1}]={2}", yz, col, a[yz, col]);                        y0++;
                    }
                }            }
            else
            {
                for (row = row1; row < row2; row++)
                {
                    double x0 = (row - b) / k;                    double y = row + 1;
                    double x = (y - b) / k;
                    double p = Math.Ceiling(x - x0);                    for (double ddd = Math.Floor(x0); ddd < x; ddd += 1)
                    {
                        int xz = (int)(ddd);
                        a[row, xz] = lineID;
                        Console.WriteLine("a[{1},{0}]={2}", row, xz, a[row, xz]);
                    }                    //for (j = 0; j < p; j++)
                    //{
                    //    int xz = (int)(x0);
                    //    a[row, xz] = lineID;
                    //    Console.WriteLine("a[{0},{1}]={2}", row, xz, a[row, xz]);
                    //    ;
                    //    x0++;
                    //}
                }            }
        }