A Normative Approach to Privacy-Preserving Recommender Systems: Integrating Matrix Factorization and Genetic Algorithms

Algorithm 2

Privacy genetic MF algorithm.

	Input: user rating matrix r, user set Users, item set Items, number of iterations N.
	Output: U, V;
	The r matrix is preprocessed to obtain the homotopy matrix R. The optimization problem is established as in equation (6);
	For n = 1 to N;
	For p in Users;
	Construct the objective function ;
	get the set of user binary groups;
	solve for the users’ hidden factor;
	End for
	For x in Items
	Construct the subobjective function ;
	obtain the set of item binary groups;
	solve for the item hidden factor;
	End for
	Return U, V