#include <iostream>
#include <fstream>

using namespace std;

void sumStats(double arr[], int size, double * mean, double * range, double * median);

// This assignment is worth 4 points

int main()
{
	ifstream inputFile;
	string fileName;
	int length = 0, k = 0;
	double placeholder;
	double * input = NULL;

	cout << "Enter file name: ";
	cin >> fileName;
	cin.ignore();

	inputFile.open(fileName);

	if(inputFile.fail())
	{
		cout << "File name not found. Try again." << endl;
		inputFile.close();
		return 0;
	}
	
	cout << "Now reading " << fileName << "..." << endl;
	while(inputFile >> placeholder)	// Find the size of the file
		length++;
	inputFile.close();
	input = new double[length];

	inputFile.open(fileName);	// Already successful the first time around
	while(inputFile >> input[k])
		k++;

	double avg, med, rge;
	sumStats(input, length, &avg, &rge, &med);

	cout << "Mean: " << avg << endl;
	cout << "Median: " << med << endl;
	cout << "Range: " << rge << endl;

	return 0;
}

void sumStats(double arr[], int size, double * mean, double * range, double * median)
{
	int index_sav;
	for(int i = 0; i < size; i++)
	{
		index_sav = i;
		for(int j = i+1; j < size; j++)
			if(arr[j] < arr[index_sav])
				index_sav = j;

		if(index_sav != i)
		{
			arr[i] += arr[index_sav];
			arr[index_sav] = arr[i] - arr[index_sav];
			arr[i] -= arr[index_sav];
		}
	}

	double sum = 0;
	for(int i = 0; i < size; i++)
		sum += arr[i];

	*mean = sum/size;

	if(size % 2 == 0)
		*median = (arr[size/2 - 1] + arr[size/2])/2;
	else
		*median = arr[size/2];

	*range = arr[size-1] - arr[0];
}