/*
?*
?*??This?file?is?part?of?MUMPS?5.0.1?released
?*??on?Thu?Jul?23?17:08:29?UTC?2015
?*
?*/
/*?Example?program?using?the?C?interface?to?the?
?*?double?real?arithmetic?version?of?MUMPS?dmumps_c.
?*?We?solve?the?system?A?x?=?RHS?with
?*???A?=?diag（1?2）?and?RHS?=?[1?4]^T
?*?Solution?is?[1?2]^T?*/
#include?
#include?
#include?“mpi.h“
#include?“dmumps_c.h“
#define?JOB_INIT?-1
#define?JOB_END?-2
#define?USE_COMM_WORLD?-987654

#if?defined（MAIN_COMP）
/*
?*?Some?Fortran?compilers?（COMPAQ?fort）?define?main?inside
?*?their?runtime?library?while?a?Fortran?program?translates
?*?to?MAIN_?or?MAIN__?which?is?then?called?from?“main“.?This
?*?is?annoying?because?MAIN__?has?no?arguments?and?we?must
?*?define?argc/argv?arbitrarily?!!
?*/
int?MAIN__（）;
int?MAIN_（）
??{
????return?MAIN__（）;
??}

int?MAIN__（）
{
??int?argc=1;
??char?*?name?=?“c_example“;
??char?**?argv?;
#else
int?main（int?argc?char?**?argv）
{
#endif
??DMUMPS_STRUC_C?id;
??MUMPS_INT?n?=?2;
??MUMPS_INT?nz?=?2;
??MUMPS_INT?irn[]?=?{12};
??MUMPS_INT?jcn[]?=?{12};
??double?a[2];
??double?rhs[2];

??MUMPS_INT?myid?ierr;
#if?defined（MAIN_COMP）
??argv?=?&name;
#endif
??ierr?=?MPI_Init（&argc?&argv）;
??ierr?=?MPI_Comm_rank（MPI_COMM_WORLD?&myid）;
??/*?Define?A?and?rhs?*/
??rhs[0]=1.0;rhs[1]=4.0;
??a[0]=1.0;a[1]=2.0;

??/*?Initialize?a?MUMPS?instance.?Use?MPI_COMM_WORLD?*/
??id.job=JOB_INIT;?id.par=1;?id.sym=0;id.comm_fortran=USE_COMM_WORLD;
??dmumps_c（&id）;
??/*?Define?the?problem?on?the?host?*/
??if?（myid?==?0）?{
????id.n?=?n;?id.nz?=nz;?id.irn=irn;?id.jcn=jcn;
????id.a?=?a;?id.rhs?=?rhs;
??}
#define?ICNTL（I）?icntl[（I）-1]?/*?macro?s.t.?indices?match?documentation?*/
/*?No?outputs?*/
??id.ICNTL（1）=-1;?id.ICNTL（2）=-1;?id.ICNTL（3）=-1;?id.ICNTL（4）=0;
/*?Call?the?MUMPS?package.?*/
??id.job=6;
??dmumps_c（&id）;
??id.job=JOB_END;?dmumps_c（&id）;?/*?Terminate?instance?*/
??if?（myid?==?0）?{
????printf（“Solution?is?:?（%8.2f??%8.2f）\n“?rhs[0]rhs[1]）;
??}
??ierr?=?MPI_Finalize（）;
??return?0;
}