#include #include #include int size, rank; int root = 0; int main(int argc, char * argv[]) { int sum = 0; MPI_Init(&argc, &argv); MPI_Comm_rank(MPI_COMM_WORLD, &rank); MPI_Comm_size(MPI_COMM_WORLD, &size); for(int i = 0; i < 4; i++) { MPI_Reduce(&i, &sum, 1, MPI_INT, MPI_SUM, root, MPI_COMM_WORLD); if(!rank)printf("sum=%d\n", sum); $mpi_coassert(MPI_COMM_WORLD, sum@(root + 1 - 1) == (i*size)); } MPI_Finalize(); return 0; }