Multiobjective Personalized Recommendation Algorithm Using Extreme Point Guided Evolutionary Computation

Algorithm 2

Fast_Non_Dominated_Sort(Epa).

 Input the population Epa

 for each  pEpa

     S_p =, M_P = 0

     for each  qEpa

     if (pq) then    // If p dominates q

     S_p = S_p     // Add q to the set of solutions dominated by p

     else if (qp) then

     M_P = M_P +1   // Increment the domination counter of p

       if  M_P = 0 then    // p belongs to the first front

      = 1

     F₁ = F₁

 i=1           // Initialize the front counter

 while  F_i

   S =          // Used to store the members of the next front

   for each pF_i

   for each qS_p

     M_q = M_q -1

     if M_q = 0 then  // q belongs to the next front

     q_rank = i+1

     H = H

 i = i+1

 F_i = H

 Return F_i