The 2d array prints incorrect numbers

[Torex]

Hi everyone. I'm having issues with this program. This program counts a sum of elements which are above the reverse diagonal and which are greater than 0.
For example:

-2 1 2
3 4 5
6 7 8

The answer should be like this:

The sum of the 1st column: 3
The sum of the 2nd column: 1

However some compilers give a right answer and some of them prints insanely large numbers. Where is the problem? Is it connected with a formats of variables or what?

 #include <iostream>
#include <iomanip>

using namespace std;

int main()
{
	int n, A[10][10];
	int B[10];
	cout << "Input the size of 2d array:" << endl;

	cin >> n;

    if(n<0)
    {
        cout << "\nYou can't create a 2d array with this number" << endl;
        return 1;
    }

	cout << "Input the elements of a 2d array by lines" << endl;

	for (int i = 0; i<n; i++) // 
	{
		for (int j = 0; j<n; j++)
		{
			cin >> A[i][j]; // Input of the elements to the array
		}
	}

	cout << "\nYour 2d array" << endl; 

	for (int i=0; i<n; i++)
    {
        for(int j=0; j<n; j++)
        {
            cout << setw(5) << A[i][j]; // Control print
        }
        cout << endl;
    }

	for (int i = 0; i<n; i++)
	{
		for (int j = 0; j<n; j++)
		{
		    if(i + j < n - 1)
            {
				if(A[i][j] > 0)
				{
                    B[j] = B[j] + A[i][j];
				}
            }
		}
	}

	cout << endl;

    for(int j = 0; j <n-1; j++)
    {
        if(B[j] == 0)
         cout << j+1 << "there are no elements which are greater than 0 in this column" << endl;
        else
        cout << j+1 << " the sum of the column is: " << B[j] << endl;
    }

	return 0;
}

[Chervil]

Array B contains garbage, it is not initialised.

	int B[10] = { 0 };

[Torex]

Thank's a lot.

And one more question. If I want to give back the answer as a value with function, how should I declare variables inside?

#include <iostream>
#include <iomanip>

using namespace std;

int function(int n, ???);

int main()
{
	int n, A[10][10];
	int B[10];
	cout << "Input the size of 2d array:" << endl;

	cin >> n;

    if(n<0)
    {
        cout << "\nYou can't create a 2d array with this number" << endl;
        return 1;
    }

	cout << "Input the elements of a 2d array by lines" << endl;

	for (int i = 0; i<n; i++) // 
	{
		for (int j = 0; j<n; j++)
		{
			cin >> A[i][j]; // Input of the elements to the array
		}
	}

	cout << "\nYour 2d array" << endl; 

	for (int i=0; i<n; i++)
    {
        for(int j=0; j<n; j++)
        {
            cout << setw(5) << A[i][j]; // Control print
        }
        cout << endl;
    }

    function(int n, ????);

    for(int j = 0; j <n-1; j++)
    {
        if(B[j] == 0)
         cout << j+1 << "there are no elements which are greater than 0 in this column" << endl;
        else
        cout << j+1 << " the sum of the column is: " << B[j] << endl;
    }

	return 0;
}

int function(int n, ???)
{
        for (int i = 0; i<n; i++)
	{
		for (int j = 0; j<n; j++)
		{
		    if(i + j < n - 1)
            {
				if(A[i][j] > 0)
				{
                    B[j] = B[j] + A[i][j];
				}
            }
		}
	}
        return ???
}

[Chervil]

If I want to give back the answer as a value with function, how should I declare variables inside?

Since the result is an array of several values, rather than a single number, the function will return the results via the array B[]. Thus it doesn't need to be declared as int function(... .

The function header could look line this:

void function(int n, int A[10][10], int B[10])

and you would call it like this:

    function(n, A, B);

I'd suggest if you do that, it seems reasonable that the function might be called more than once, thus it should reset the contents of array B[] to all zeros each time.