What is the runtime of this algorithm, expressed as a function of the number of objects to rank?

Recall the algorithm that was given in the text and in class for testing a ranking algorithm.

Algorithm 20 RANKTEST(f, , obj) 1: if obj contains 0 or 1 elements then return obj 3 else 4 p+ randomly chosen object in obj // pick pivot 5 left O Il elements that seem smaller than p right + 0 Il elements that seem larger than p 7 for all u e obj \{p} do 9 +f(xup) // what is the probability that u precedes p if uniform random variable