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


// generate an input file to test the program... not required
void generateInputFile(char *filename);
void generateInputFile(char *filename)
{
	// produce a file containing 100 random integers between 1 and 1000
	FILE* outFilePtr = NULL;
	int c;
	int n;

	srand(time(NULL));

	outFilePtr = fopen(filename, "w");
	if (outFilePtr == NULL)
	{
		// something wrong
		fprintf(stderr, "Error: something is wrong in opening the file...\n");
		return;
	}
	
	// write the random numbers

	for(c = 0 ; c < 100; c++)
	{
		n = 1 + (rand() % 1000);   // a random number between 1 and 1000
	
		if ( c == 0)
		{
			fprintf(outFilePtr, "%d", n);
		}
		else
		{
			fprintf(outFilePtr, "\n%d", n);
		}
	}


	fclose(outFilePtr);
}

int main()
{
	FILE* inFilePtr = NULL;
	FILE* outFilePtr = NULL;

	int counter = 0;		// keep track of how many numbers are read from the file so far
	int n;				// current number from file
	int min;			// smallest number seen so far
	int max;			// largest number seen so far
	int sum = 0;			// ongoing sum of all the numbers n read so far
	float avg = 0;			// average: sum/n

	// Create a random file to test
	generateInputFile("in.dat");

	// read file
	inFilePtr = fopen("in.dat", "r");
	if (inFilePtr == NULL)
	{
		// something wrong
		fprintf(stderr, "Error: something is wrong in opening the file...\n");
		return -1;
	}

	while(!feof(inFilePtr))
	{
		fscanf(inFilePtr, "%d", &n);
		counter++;
		sum+=n;
		if (counter == 1)
		{
			min = n;
			max = n;
		}
		else
		{
			if (n < min) min = n;
			if (n > max) max = n;	
		}
	}

	fclose(inFilePtr);

	// compute
	avg = sum / counter;

	// store results
	outFilePtr = fopen("out.dat", "w");
	if (outFilePtr == NULL)
	{
		// something wrong
		fprintf(stderr, "Error: something is wrong in opening the file...\n");
		return -1;
	}
	
	fprintf(outFilePtr, "%d %d %.2f", min, max, avg);

	fclose(outFilePtr);

	return 0;
}