#include<stdio.h>
#include<stdlib.h>
#include<stdlib.h>
#define n 3

/*__global__ void kernel(int **support[],int size)
{
	
	int i=threadIdx.x;
	int j=threadIdx.y;
	if(i<size)
		support[i*size+j]=10;
}
*/
int main()
{
	long int **matrix=NULL;
	long int **dev_matrix=NULL;
	long int **support=NULL;
	int i,j,er=1000;
	long int **result=NULL;
   int size;
   matrix=(long int **)malloc(sizeof(long int *)*n);
	for(i=0;i<n;i++)
	{
		matrix[i]=(long int *)calloc(n,sizeof(long int));
	}
	
	result=(long int **)malloc(sizeof(long int *)*n);
	for(i=0;i<n;i++)
	{
		result[i]=(long int *)calloc(n,sizeof(long int));
	}
	for(i=0;i<n;i++)
	{
		for(j=0;j<n;j++)
			{
				result[i][j]=100;
			}
		printf("\n");
	}
	printf("Result before copy:\n");
	for(i=0;i<n;i++)
	{
		for(j=0;j<n;j++)
			{
				printf("%ld\t",result[i][j]);
			}
		printf("\n");
	}
	
	
	//pointer array to store list of elements
	er=cudaMalloc((void **) &dev_matrix,n*sizeof(long int *));
	if(er) printf("%d Error in allocation",er);
	//For copying the pointers to GPU this support helps
	support = (long int **) malloc(sizeof(long int*)*n);
	
	//Copied the support vector of the pointers
	er=cudaMemcpy(support,dev_matrix,n*sizeof(long int*),cudaMemcpyDeviceToHost);
	if(er) printf("%dError in copying the pointers",er);
	for (i=0;i<n;++i) 
	{
		//printf("hello");	
		er=cudaMalloc((void**)&support[i],sizeof(long int)*n);
		if(er) printf("%dError in allocation",er);
	}
	
	for(i=0;i<n;i++)
	{
	
		for(j=0;j<n;j++)
		{
			//printf("I am coming from device to host:\n");
			cudaMemcpy(support[i*n+j],matrix[i*n+j],sizeof(long int),cudaMemcpyHostToDevice);
		}
	}
	size=n;
	/*for(i=0;i<n;i++)
	{
	kernel<<<1,n>>>(dev_matrix[i],size);
	}*/
	for(i=0;i<n;i++)
	{
		
		for(j=0;j<n;j++)
		{
			//printf("I am coming from device to host:\n");
			cudaMemcpy(result[i*n+j],support[i*n+j],sizeof(long int),cudaMemcpyDeviceToHost);
		}
	}
	printf("Result after copy:\n");
	for(i=0;i<n;i++)
	{
		for(j=0;j<n;j++)
			{
				printf("Element[%d][%d]=%ld\t",i,j,result[i][j]);
			}
		printf("\n");
	}
	

return 0;
}



/*
The output that get is 
Result before copy:
100	100	100	
100	100	100	
100	100	100	

Result after copy:
Element[0][0]=0	Element[0][1]=100	Element[0][2]=100	
Element[1][0]=0	Element[1][1]=100	Element[1][2]=100	
Element[2][0]=0	Element[2][1]=100	Element[2][2]=100	



*/