All points except for one lie on a line. Which one is the outlier?
You are given a list of x-y pairs in a column like this:
pts = [ 0 1 0 2 3 2 0 3 0 4 ]
You would return the number 3, since the third point is the only one that is non-collinear with the other points. All the others are on the y-axis.
outlier = 3