Grade array trouble

[xterragator]

I'm having some trouble with my sum not adding up properly, I'm not exactly sure what's going on here. I'm new to C++ and still trying to get this stuff down.

A user tells the program how many students there are (up to 250). Each student has 8 grades. My problem is when I try to average a project grade for the entire "class" the sum of the grades does something that I really don't understand.

Here's where I input the grades:
int students;
int projects=7;
int grades[250][8];
int number;
//these are all outside of int main()


cout << "Please give number of students: ";
cin >> students;

for (int i=0; i<=projects; i++) {
for (int j=0; j<=students-1; j++) {
cout << "Please give grade of student " << j+1 << " in project " << i+1 << ":";
cin >> grades[i][j];


And here's where the problem starts:

int projectavg;
int sum=0;

cout << "Give the number of the project: ";
cin >> number;

for (int i=0; i<=students; i++) {
sum=sum+grades[i][number];
}
projectavg=sum/students;
cout << sum << endl;


I chose to print the sum to make sure it was spitting out the correct value, which it isn't.

So if you could give me some tips, that'd be awesome! Thanks!

[Zhuge]

In your first for loop, you go from 0 to students-1 inclusive, and in your second, you go from 0 to students inclusive. Your ranges don't match.

[xterragator]

Thanks I figured it out!

I had grades[i][j] instead of grades[j][i]..