how to find a line which is perpendicular to a given line programmaticlly ???

zlly20

Say, I have a line  A :

y = a * x + b

now I want to find another line which is perpendicular to A at point M [m, n] and M is on A:

y1 = a1 * x1 + b1

what is the simplest way to do it programmatically in c++???

gamedragon

a1=-1/a (a!=0)

bookstack

用lex && yacc 来分析：

y = a * x + b
var_0 = var_1 times var_2 plus var_3

得到syntax tree以后，遍历找相似的。

gamedragon

楼主问的是语法分析的问题么？难道我理解错了？
perpendicular不是垂直的意思么？