#include <stdio.h> #include "mpi.h" int main( argc, argv ) int argc; char **argv; { int rank, value, size; MPI_Status status; MPI_Init( &argc, &argv ); MPI_Comm_rank( MPI_COMM_WORLD, &rank ); MPI_Comm_size( MPI_COMM_WORLD, &size ); do { if (rank == 0) { scanf( "%d", &value ); MPI_Send( &value, 1, MPI_INT, rank + 1, 0, MPI_COMM_WORLD ); } else { MPI_Recv( &value, 1, MPI_INT, rank - 1, 0, MPI_COMM_WORLD, &status ); if (rank < size - 1) MPI_Send( &value, 1, MPI_INT, rank + 1, 0, MPI_COMM_WORLD ); } printf( "Process %d got %d\n", rank, value ); } while (value >= 0); MPI_Finalize( ); return 0; }