program f77_main

      integer maxn, maxnz

      parameter ( maxn = 10000, maxnz = 100000 )

      integer rowind(maxnz), colptr(maxn)

      real*8  values(maxnz), b(maxn)

      integer n, nnz, nrhs, ldb, info

      integer factors(8), iopt

*

      call hbcode1(n, n, nnz, values, rowind, colptr)

*

      nrhs = 1

      ldb = n

      do i = 1, n

         b(i) = 1

      enddo

*

* First, factorize the matrix. The factors are stored in factor() handle.

      iopt = 1

      call c_fortran_dgssv( iopt, n, nnz, nrhs, values, rowind, colptr, 

     $                      b, ldb, factors, info )

*

      if (info .eq. 0) then

         write (*,*) 'Factorization succeeded'

      else

         write(*,*) 'INFO from factorization = ', info

      endif

*

* Second, solve the system using the existing factors.

      iopt = 2

      call c_fortran_dgssv( iopt, n, nnz, nrhs, values, rowind, colptr, 

     $                      b, ldb, factors, info )

*

      if (info .eq. 0) then

         write (*,*) 'Solve succeeded'

         write (*,*) (b(i), i=1, 10)

      else

         write(*,*) 'INFO from triangular solve = ', info

      endif

* Last, free the storage allocated inside SuperLU

      iopt = 3

      call c_fortran_dgssv( iopt, n, nnz, nrhs, values, rowind, colptr, 

     $                      b, ldb, factors, info )

*

      stop

      end