2 Problem 1. Recursion-Video rankings. ( 8 marks) The InitaVid social network collocts user preierebces by ading them to rank their favorite videos. One of the features of InstaVid is offering friendahip sucomtions for mers with similar tastes, using the following metric. If user One ranks the videos using the sequence 1,2,,n, and user Two rakios ame vidoos wing the sequence c1,v2,,vn of numbens 1,2,,n, then their social distance is computed by counting all pairs ( rw,y ) from the ranking of Two that satisfy the condition vi>r, for i.