Implement the summation of four vectors, each of N doubles, with an algorithm similar to the reduction algorithm. The final sum should be available on all processes. Use four processes. Each of them...

Implement the summation of four vectors, each of N doubles, with an algorithm

similar to the reduction algorithm. The final sum should be available on all

processes. Use four processes. Each of them will initially generate its own

vector. Use MPI point-to-point communication to implement your version of

the summation of the generated vector. Test your program for small and large

vectors. Comment results and compare the performance of your implementation

with that of the MPI_ALLREDUCE. Explain any differences.