MODULE Network_Data_Structures
      USE Precision
      USE Error_Handling
      USE System_Monitors
      IMPLICIT NONE
      PRIVATE
      
      INTEGER(KIND=i_wp),PUBLIC,SAVE::n_nodes,n_arcs,n_special_nodes,n_special_arcs
      INTEGER,PARAMETER,PUBLIC::n_dim=2
      INTEGER(KIND=i_wp),DIMENSION(:,:),ALLOCATABLE,TARGET,PUBLIC::heads_tails
      REAL,DIMENSION(:,:),ALLOCATABLE,TARGET,PUBLIC::nodes_coords
      REAL(KIND=r_wp),DIMENSION(:),ALLOCATABLE,TARGET,PUBLIC::&
      nodes_potentials,supplies_demands
      REAL(KIND=r_wp),DIMENSION(:),ALLOCATABLE,TARGET,PUBLIC::arcs_flows,arcs_voltages
      LOGICAL(KIND=l_wp),DIMENSION(:),ALLOCATABLE,PUBLIC::arcs_mask,nodes_mask
      
      INTEGER,PUBLIC,SAVE::n_cost_parameters
      REAL(KIND=r_wp),DIMENSION(:,:),ALLOCATABLE,TARGET,PUBLIC::arcs_cost_parameters
      
      INTEGER(KIND=i_wp),PUBLIC,SAVE::n_regular_cost_arcs=0,n_high_cost_arcs=0,n_low_cost_arcs=0,&
      n_regular_nodes=0,n_fixed_potential_nodes=0
      INTEGER(KIND=i_wp),DIMENSION(:),ALLOCATABLE,PUBLIC::&
      special_arcs_status,special_nodes_status
      INTEGER(KIND=i_wp),PARAMETER,PUBLIC::dummy_arc=0,low_cost_arc=1,high_cost_arc=2,regular_cost_arc=3
      INTEGER(KIND=i_wp),PARAMETER,PUBLIC::fixed_potential_node=1,dummy_node=2,regular_node=3
      
      END MODULE Network_Data_Structures