#include <iostream>
#include <cstdlib>
#include <cstring>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <unistd.h>
#define SHM_KEY 1234

using namespace std;

int main(int argc, char **argv) {
	if (argc<2|| argc>3) {
		cout<<"Usage:./as2 N [delete]" <<endl;
		return 1;
	}
	int n=atoi(argv[1]);
	bool deleteShm = false;
	if (argc==3 && strcmp(argv[2],"delete")==0) {
		deleteShm = true;
	}
	int shmId = shmget(SHM_KEY,0,0666);
	if (shmId<0){
		cout << "memory does not exist!"<< endl;
		return 1;
	}
	cout <<"Memory found with shmid= " << shmId << endl;
	int *matrix = (int *) shmat(shmId,NULL,0);
	//row major
	for (int row = 0;row<n;row++) {
		for (int col = 0;col<n;col++) {
			cout << matrix[row*n+col] <<" ";
		}
		cout<<endl;
	}

	if (deleteShm) {
		shmctl(shmId, IPC_RMID, NULL);
		cout << "Memory deleted!" << endl;
	}
	return 0;
}