updated p2

hw2/skeleton/p2/Makefile

 CFLAGS = -O3
-LDFLAGS = -lblas
+LDFLAGS = -lopenblas
 CC =$(shell which mpicxx)
 
 .SECONDARY: 

hw2/skeleton/p2/auxiliar/auxiliar.cpp

 #include "auxiliar.hpp"
 #include <math.h>
 #include <mpi.h>
+#include <stdio.h>
+#include <stdlib.h>
 
 void initializeMatrices(double* A, double* B, const int n, const int N, const int rankx, const int ranky)
 {