$*$ You are required to modify the MPI code so that, instead of using MPI$\_$Allgather, it uses the non$-$blocking send and receive messages.

$*$ This must be done without affecting correctness.

$**/$

$//============================================================================$

#include

#include

#include

#define N $4$

int main$($int argc, char $*$argv$[])\{$

int rank, P;

int i$,$ j;

int sbuff$[$N$][$N$]$;

int$*$ rbuff;

MPI$\_$Init$($&argc, &argv$)$;

MPI$\_$Comm$\_$rank$($MPI$\_$COMM$\_$WORLD, &rank$)$;

MPI$\_$Comm$\_$size$($MPI$\_$COMM$\_$WORLD, &P$)$;

for$($i$=0$; i