Histogram/loop issues

[Octoballa]

Trying to take my gradeScale array, which holds all the grades the user enters, and create a histogram that would tally up how many as, bs, cs, ds, and fs there are. This would be counted in the bin array. However, my loop isnt working.

#include <iostream>

using namespace std;

void inputArray(int*, int*);
void calculate(int*, int*, int*, int*);
//void display();

int main() {
	int studentGrades[30];
	int gradeScale[101];
	int bin[5];
	int values = 0;
	
	inputArray(studentGrades, &values);
	calculate(studentGrades, gradeScale, bin, &values);

	cout << "grade = " << gradeScale[10] << endl;
	cout << "grade = " << gradeScale[50] << endl;
	cout << "fs = " << bin[0] << endl;
	cout << "ds = " << bin[1] << endl;
	cout << "cs = " << bin[2] << endl;
	cout << "bs = " << bin[3] << endl;
	cout << "as = " << bin[4] << endl;

	system ("pause");
	return 0;
}

void inputArray(int *studentGrades, int *values) {
	
	cout << "Enter test score for student " << *values + 1 << " (or -1 to quit): ";
	cin >> studentGrades[*values];

	while (studentGrades[*values] != -1) {
		++(*values);
		cout << "Enter test score for student " << *values + 1 << " (or -1 to quit): ";
		cin >> studentGrades[*values];
	}
}

void calculate(int *studentGrades, int *gradeScale, int *bin, int *values) {
	int ticker = 0;

	for (int index = 0; index < 101; index++)
		gradeScale[index] = 0;

	for (int index = 0; index < *values; index++) {
		int score = studentGrades[index];
		gradeScale[score] += 1;
	}

	for (int index = 0; index < 5; index++)
		bin[index] = 0;

	for (int index = 0; index < *gradeScale; index++) {
		if (gradeScale[index] <= 59) 
			bin[0] += 1;
		else if (gradeScale[index]>= 60 && gradeScale[index] <=69) 
				bin[1] += 1;
		else if (gradeScale[index]>= 70 && gradeScale[index] <=79) 
				bin[2] += 1;
			else if (gradeScale[index]>= 80 && gradeScale[index] <=89) 
				bin[3] += 1;
			else if (gradeScale[index]>= 90 && gradeScale[index] <=100) 
				bin[4] += 1;
		}
}

//void display() 

[Smac89]

which loop isn't working exactly? You have more than one loop

[Octoballa]

The last one(last group of if statements.). Its supposed to use the bin array to count how many of each letter grade there are for a histogram.

[Octoballa]

Anyone?

[coder777]

I'd say that on line 56 index < *gradeScale is wrong (supposed to be index < *values?)

Further more gradeScale seems to contain the amount of the percentage not the actual percentage itself. So I'd guess that you should use studentGrades instead?