How to Write Publisher Subscriber for a arrray in ROS C++ ?

edit

I found a code reference for publisher subscriber with array msg in a topic, but then i couldnt find the error im doing in it. Please help me in finding the error.

Publisher Program:

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

#include "ros/ros.h"

#include "std_msgs/MultiArrayLayout.h"
#include "std_msgs/MultiArrayDimension.h"

#include "std_msgs/Int32MultiArray.h"

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


    ros::init(argc, argv, "arrayPublisher");

    ros::NodeHandle n;

    ros::Publisher pub = n.advertise<std_msgs::Int32MultiArray>("array", 100);

while (ros::ok())
{
    std_msgs::Int32MultiArray array;
    //Clear array
    array.data.clear();
    //for loop, pushing data in the size of the array
    for (int i = 0; i < 12; i++)
    {
        //assign array a random number between 0 and 180.
        array.data.push_back(rand() % 180);
    }
        //Publish array
        pub.publish(array);
        //Let the world know
        ROS_INFO("I published something!");
        //Do this.
        ros::spinOnce();
        //Added a delay so not to spam
        sleep(2);
    }

}

Subscriber program:

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

    #include <iostream>

#include "ros/ros.h"

#include "std_msgs/MultiArrayLayout.h"
#include "std_msgs/MultiArrayDimension.h"
#include "std_msgs/Int32MultiArray.h"

int Arr[90];
void arrayCallback(const std_msgs::Int32MultiArray::ConstPtr& array);

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

    ros::init(argc, argv, "arraySubscriber");

    ros::NodeHandle n;  

    ros::Subscriber sub3 = n.subscribe("array", 100, arrayCallback);



    for(int j = 1; j < 12; j++)
    {
        printf("%d, ", Arr[j]);
    }

    printf("\n");
    ros::spinOnce();
}

void arrayCallback(const std_msgs::Int32MultiArray::ConstPtr& array)
{

    int i = 0;
    // print all the remaining numbers
    for(std::vector<int>::const_iterator it = array->data.begin(); it != array->data.end(); ++it)
    {
        Arr[i] = *it;
        i++;
    }

    return;
}

While checking the topic , the values are publishing properly. But in the subscriber node something is going wrong i dont know where it is!

Thanks you!