#include <iostream>
#include <cstdlib>

using namespace std;

int main();
void sortScores(int*, int);
double getAverage(int *, int);
char grade(int);

int main() {
	int numScores, i;
	cout << "How many scores will you enter? ";
	cin >> numScores;

	if (numScores < 1) {
		cerr << "Invalid number of scores" << endl;
		return 1;
	}

	int *scores;
	
	if ((scores = (int*) malloc(sizeof(int) * numScores)) == NULL) {
		cerr << "Error allocating memory for your scores" << endl;
		return 1;
	}

	for (i = 0; i < numScores; i++) {
		cout << "Score (" << (i+1) << "/" << numScores << ") "; 
		cin >> i[scores];

		// Input validation; ask them for this one again if it's at least 0
		if (*(scores+i) < 1) 
			i--;
	}

	sortScores(scores, numScores);

	cout.setf(ios::fixed,ios::floatfield);
	cout.precision(2);
	cout << "Average score: " << getAverage(scores, numScores) << endl;
	cout << "Student Scores" << endl;
	cout << "--------------" << endl;

	for (i = 0; i < numScores; i++) 
		cout << "(" << grade(*(scores+i)) << ") " << *(scores+i) << endl;
	
	return 0;
}

void sortScores(int *scores, int n) {
	int smallest, i, j;
	for (i = 0; i < n - 1; i++)  {
		smallest = i;
		for (j = i; j < n; j++) 
			if (*(scores + smallest) > *(scores + j))
				smallest = j;
		
		swap(*(scores+i), *(scores + smallest));
	}
}	

double getAverage(int *scores, int n) {
	double total = 0;
	for (int i = 0; i < n; i++)
		total += *(scores+i);
	return total / n;
}

char grade(int score) {
	if (score >= 90)
		return 'A';
	if (score >= 80)
		return 'B';
	if (score >= 70)
		return 'C';
	if (score >= 60)
		return 'D';
	return 'F';
}