A Heuristic Procedure for a Ship Routing and Scheduling Problem with Variable Speed and Discretized Time Windows

Pseudocode 2

Pseudocode of the Local Search Procedure.

Local-Search()

Input: 𝑥≔ Initial Feasible solution (Route for each ship 𝑘)

Output: 𝑥^∗≔ Best Solution found (Route for each ship 𝑘)

 Do until no further improvement is achieved

  InsertionContractsN()

  ImproveRoute()

 End do

 Do until no further improvement is achieved

  InterchangeContractsN()

  ImproveRoute()

 End do

 Do until no further improvement is achieved

  2OptUpward()

  ImproveRoute()

 End do

 Do until no further improvement is achieved

  InsertionContractsN2()

  ImproveRoute()

 End do

 If no improvement of the initial solution was found, then

  InterchangeContracts_S()

  If no improvement was previously found, then

   InterchangeContracts_C()

  End if

 End If

 Return 𝑥^∗