Write a MPI program to find sum of N numbers.

Q. Write a MPI program to find sum of N numbers. (MAY 19) 10M

Ans-  MPI program to find sum of N numbers

#include <bits/stdc++.h>

#include "mpi.h"

using namespace std;

int main(int argc, char ** argv)

{

int myrank,res,p,dst = 0,tag = 0,ar[100],i;

for(int i=0;i<100;i++)

ar[i] = i;

MPI_Status status;

MPI_Init (&argc, &argv);

MPI_Comm_rank(MPI_COMM_WORLD, &myrank);

MPI_Comm_size(MPI_COMM_WORLD, &p);

if(myrank != 0)

{

int interval = 100/(p-1),x,y;

x = interval*(myrank-1);

y = interval*(myrank)-1;

res = 0;

for(i=x;i<=y;i++)

res+=ar[i];

// cout<<"sum "<<res <<"\n";

MPI_Send(&res, sizeof(res), MPI_INT, 0, 0, MPI_COMM_WORLD);

}

else

{

int sum = 0;

for(int src= 1; src< p; src++)

{

MPI_Recv(&res, sizeof(res), MPI_INT, src, 0, MPI_COMM_WORLD, &status);

printf("sum recieved from the process: %d is %d\n",src, res);

sum = sum + res;

}

printf("the total sum is %d\n",sum);

}

 

MPI_Finalize();

}