search for: 301249

I am trying to simulate a self avoiding random walk in 2d of length 100. So I am using two vectors of length 100 to encode the x and y coordinates. At each step I want apply a orthogonal transformation at a random point and then check to see if the walk intersects with itself. This amounts to simply checking to see if any of the ordered pairs of (x,y) coordinates in 1:j are repeated in j+1:100.