module commondata
    implicit none
    
    integer, parameter :: kn = 4
    real*8, parameter :: pi = 3.1415926535898d0
    real*8, parameter :: eps = 1.0d-20
    real*8, parameter :: epsilon = 1.0d-20
    integer :: FLG_continue, FLG_prob, FLG_split, FLG_order, FLG_recon
    integer :: im, jn, nrk
    integer :: ifs, jfs    !  ǰ̨׽ǵλ
    integer :: i, j, k
    real*8 :: gamma, t_end, xlong, ylong, dx, dy, dt, tn, CFL
    real*8, allocatable :: xr(:,:), ys(:,:), var(:,:,:), v0(:,:,:), v1(:,:,:), vtemp(:,:,:)
    real*8, allocatable :: fxp(:,:,:), fxm(:,:,:), fyp(:,:,:), fym(:,:,:)
    real*8, allocatable :: fx(:,:,:), fy(:,:,:)
    ! var--ԭʼ--rho, u, v, p, c
    ! v0,v1--غ--rho, rho*u, rho*v, E
    ! fp--ͨ;  fm--ͨ;  f--fluxͨ
    
end module commondata