Circuit satisfiablity exhaustive search using MPI

circuit_mpi.c

# include <stdlib.h>
# include <stdio.h>
# include <mpi.h>
# include <time.h>
# define N 23

void to_bin(int val, int bvec[])
{
    int i;
    for (i=0; i<N; i++) 
        bvec[i] = (val & (1<<i)) ? 1 : 0;
}

int circuit_value(int bvec[])
{
    return (  bvec[0]  ||  bvec[1]  )
        && ( !bvec[1]  || !bvec[3]  )
        && (  bvec[2]  ||  bvec[3]  )
        && ( !bvec[3]  || !bvec[4]  )
        && (  bvec[4]  || !bvec[5]  )
        && (  bvec[5]  || !bvec[6]  )
        && (  bvec[5]  ||  bvec[6]  )
        && (  bvec[6]  || !bvec[15] )
        && (  bvec[7]  || !bvec[8]  )
        && ( !bvec[7]  || !bvec[13] )
        && (  bvec[8]  ||  bvec[9]  )
        && (  bvec[8]  || !bvec[9]  )
        && ( !bvec[9]  || !bvec[10] )
        && (  bvec[9]  ||  bvec[11] )
        && (  bvec[10] ||  bvec[11] )
        && (  bvec[12] ||  bvec[13] )
        && (  bvec[13] || !bvec[14] )
        && (  bvec[14] ||  bvec[15] )
        && (  bvec[14] ||  bvec[16] )
        && (  bvec[17] ||  bvec[1]  )
        && (  bvec[18] || !bvec[0]  )
        && (  bvec[19] ||  bvec[1]  )
        && (  bvec[19] || !bvec[18] )
        && ( !bvec[19] || !bvec[9]  )
        && (  bvec[0]  ||  bvec[17] )
        && ( !bvec[1]  ||  bvec[20] )
        && ( !bvec[21] ||  bvec[20] )
        && ( !bvec[22] ||  bvec[20] )
        && ( !bvec[21] || !bvec[20] )
        && (  bvec[22] || !bvec[20] );
}

int main (int argc, char *argv[])
{
    int bvec[N], i, j, id, p;
    int ihi, ihi2, ilo, ilo2;
    int solution_num_local, solution_num;
    MPI_Init (&argc, &argv);
    MPI_Comm_rank (MPI_COMM_WORLD, &id);
    MPI_Comm_size (MPI_COMM_WORLD, &p);
    ilo = 0;
    ihi = 1<<N;
    ilo2 = ((p-id)*ilo + (id)*ihi)/p;
    ihi2 = ((p-id-1)*ilo + (id+1)*ihi)/p; 
    solution_num_local = 0;
    for(i=ilo2; i<ihi2; i++) {
        to_bin(i, bvec);
        if(circuit_value(bvec)) {
            ++solution_num_local;
            printf("\n%2d  %8d  %10d:  ", solution_num_local, id, i);
            for (j=0; j<N; j++)
                printf(" %d", bvec[j]);
            printf ( "\n" );
        }
    }
    MPI_Reduce(&solution_num_local, &solution_num, 1, MPI_INT, MPI_SUM, 0, MPI_COMM_WORLD);
    if(id == 0) {
        printf ("Number of solutions found was %d\n", solution_num);
    }
    MPI_Finalize ( );
    return 0;
}