Perfect Numbers (mangled class notes)

[barrelroll]

I took these notes in class, and mangled them somehow. For the life of me, I can't figure out where the error is. It's meant to find perfect numbers. A perfect number is a number that is the sum of its divisors (minus itself). Thanks for taking a look- I really appreciate it.

#include <iostream>

using namespace std;

int main()
{
	int n,k;
	int sum;
	for(n=2;n<=10000;n++) //we're trying to see if n is perfect.
	{
		sum=0;
		for(k=n/2;k<=n/2;k++)  //if k<=n/2 and sum <=n  
		//also k should start at large end, not low.
		{
			if(n%k==0)
			sum=sum+k;
		if(sum==n)
		cout << n << " is perfect!" << endl;
		}
        }
return 0;
}

[Athar]

This is wrong:

for(k=n/2;k<=n/2;k++)

You're only checking whether n is divisible by n/2.
It should be for (k=2 1;...

[toum]

In your 2nd loop, k should start at 1, not n/2.

[Chervil]

for(k=n/2; k>0; k--)


this test needs to be moved outside the innermost for-loop,

if (sum==n)
    cout << n << " is perfect!" << endl;

[barrelroll]

Thank you very much!