#include <stdio.h>

#define MAX 10

void PopulateArray(int A[]);
void PopulateArray(int A[])
{
	int i;
	for (i=0; i < MAX; i++)
	{
		A[i] = i+1;
	}
}

int SaveArray(int A[], char *filename);
int SaveArray(int A[], char *filename)
{
	int i;
	FILE *outfileptr;

	outfileptr = fopen(filename, "w");
	if (outfileptr == NULL)
		return 0;

	for (i=0; i < MAX; i++)
	{
		if (i==0)
			fprintf(outfileptr, "%d", A[i]);
		else
			fprintf(outfileptr, " %d", A[i]);

	}

	fclose(outfileptr);
	return i;
}



int LoadArray(int A[], char *filename);
int LoadArray(int A[], char *filename)
{
	int i=0;
	FILE *infileptr;

	infileptr = fopen(filename, "r");
	if (infileptr == NULL)
		return 0;

	while(!feof(infileptr))
	{
		fscanf(infileptr, "%d", &A[i]);
		i++;
	}

	fclose(infileptr);
	return i;
}

void Reverse(int A[], int numCount);
void Reverse(int A[], int numCount)
{
	int i, temp;
	for (i=0 ; i < numCount/2; i++)
	{
		// swap A[i] with A[numCount -1 -i]
		temp = A[i];
		A[i] = A[numCount - 1 - i];
		A[numCount-1-i] = temp;
	}
}


int main()
{
	int A[MAX];
	int numCount;

	PopulateArray(A);

	numCount = SaveArray(A, "a.dat");
	printf("%d numbers saved...\n", numCount);

	numCount = LoadArray(A, "a.dat");
	printf("%d numbers loaded...\n", numCount);

	Reverse(A, numCount);
	printf("Array reversed...\n", numCount);
	
	numCount = SaveArray(A, "a.dat");
	printf("%d numbers saved...\n", numCount);
	

	return 0;
}