B. Arpa and an exam about geometry
geometry; math
Arpa is taking a geometry exam. Here is the last problem of the exam.You are given three points a, b, c.Find a point and an angle such that if we rotate the page around the point by the angle, the new position of a is the same as the old position of b, and the new position of b is the same as the old position of c.Arpa is doubting if the problem has a solution or not (i.e. if there exists a point and an angle satisfying the condition). Help Arpa determine if the question has a solution or not.
The only line contains six integers ax, ay, bx, by, cx, cy (|ax|, |ay|, |bx|, |by|, |cx|, |cy| ≤ 109). It's guaranteed that the points are distinct.
Print ""Yes"" if the problem has a solution, ""No"" otherwise.You can print each letter in any case (upper or lower).
In the first sample test, rotate the page around (0.5, 0.5) by .In the second sample test, you can't find any solution.