allgatherv.c

并行计算的一些演示程序

#include "mpi.h"

int main( int argc, char* argv[] )
{
    int i;
    int rank, nproc;
    int isend[3], iscnt, irecv[6];
    int ircnt[3] = {1,2,3}, idisp[3] = {0,1,3};
 
    MPI_Init( &argc, &argv );
    MPI_Comm_size( MPI_COMM_WORLD, &nproc );
    MPI_Comm_rank( MPI_COMM_WORLD, &rank );

    if ( rank == 0 ) printf(" This program must run with 3 processes: np = 3\n");
    
    for(i=0; i<rank+1; i++)
        isend[i] = rank + 1;
        iscnt = rank + 1;
       MPI_Allgatherv(isend, iscnt, MPI_INT, irecv, ircnt, idisp, 
                                MPI_INT, MPI_COMM_WORLD);
       for(i=0; i<6; i++)
            printf("My rank = %d irecv = %d\n", rank, irecv[i]);
    MPI_Finalize();
}