MPI_PI

#include <mpi.h>
#include <stdio.h>
#include <stdlib.h>

 # define length 100

int main(int argc, char** argv) {

    MPI_Init(&argc, &argv);

    int world_size;
    MPI_Comm_size(MPI_COMM_WORLD, &world_size);
    int rank;
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);


    //MPI_Bcast(&x, 1, MPI_INT, 0, MPI_COMM_WORLD);
    float x = 0.0f;
    x = 1.0 / (3 + 4*rank);
    float sumMinus = 0.0f;
    MPI_Reduce(&x, &sumMinus, 1, MPI_FLOAT, MPI_SUM, 0, MPI_COMM_WORLD);

    //MPI_Bcast(&x, 1, MPI_INT, 0, MPI_COMM_WORLD);
    float y= 0.0f;
    y = 1.0 / (5 + 4*rank);
    float sumPlus = 0.0f;
    MPI_Reduce(&y, &sumPlus, 1, MPI_FLOAT, MPI_SUM, 0, MPI_COMM_WORLD);


    if( rank==0 ){
        printf( "sumMinus: %f, sumPlus: %f", sumMinus, sumPlus );
        float wynik = 1 -sumMinus +  sumPlus;

        printf("\nPI/4  = %f", wynik);
        printf("\nPI = %f", wynik*4 );
    }

    MPI_Finalize();
}