#include <iostream>
#include <fstream>
#include <string>
using namespace std;

class student
{
public:  //feel free to ingore this public
	string fname;
	string lname;
	int id;
	double ex1;
	double ex2;
	double ex3;

	double average;
};

//Read one line of info from the file,
//From that info, create a student
//and return it.
student readOneStudentFromFile(ifstream &theFile)
{
	student newStudent;

	//fill students attributes/variables with the file info
	theFile >> newStudent.fname;
	theFile >> newStudent.lname;
	theFile >> newStudent.ex1;
	theFile >> newStudent.ex2;
	theFile >> newStudent.ex3;

	return newStudent;
}

//Compute average score for student x, return it
double computeAverage(student x)
{
	double avg = (x.ex1 + x.ex2 + x.ex3) / 3;
	return avg;
}

void writeOneStudentToFile(student x, ofstream &outfile )
{
	outfile << x.fname << " " << x.lname << " " << x.average << endl;
}

//Write the list of students and their average
//to the given output file
void writeStudentsToFile(student studentList[], int n, ofstream &outfile )
{
	for (int i = 0; i < n; i++)
	{
		writeOneStudentToFile(studentList[i], outfile);
	}
}



//return the index of the smallest valued exam average
//in given array from index s to index e
//Let n be number of items in search range (e-s+1)
//Run time: O( n )
int findSmallest(student list[], int s, int e)
{
	int smallestSoFar = s;
	for (int i = s; i <= e; i++)
	{
		if (list[i].average < list[smallestSoFar].average)
		{
			smallestSoFar = i;
		}
	}
	return smallestSoFar;
}

//can also do student * studentList
//sort array by average grade from index s to index e.
//Let n be number of items in given range (e-s+1)
//Run time: O( n^2 )
void selectionSort(student studentList[], int s, int e)
{
	for (int i = s; i<=e; i++)
	{
		//find smallest item from index i to e
		int smallIndex = findSmallest(studentList, i, e);

		//swap smallest item to position i
		swap(studentList[i], studentList[smallIndex]);
	}
}


int main()
{
	//step 0: opens files, etc.
	ifstream infile("studentData.txt");

	//step 1: Get number of students from file
	int numStudents;
	infile >> numStudents;

	//step 2: Make an array
	student* studentArray = new student[numStudents];

	//step 3: Read in each student's info from the file
	for (int i = 0; i < numStudents; i++)
	{
		//Step 3.1: Read in student's info
		studentArray[i] = readOneStudentFromFile(infile);
	}

	//step 4: compute average grade for each student
	for (int i = 0; i < numStudents; i++)
	{
		studentArray[i].average = computeAverage(studentArray[i]);
	}

	//step 5: sort students by average
	selectionSort(studentArray, 0, numStudents-1);

	//step 6: write students to output file
	ofstream outfile("sortedAverage.txt");
	writeStudentsToFile(studentArray, numStudents, outfile);

	return 0;
}