can't find the mistake

[specbk]

Can someone tell me where is the mistake in this code? It's supposed to have one according to my uni-test, but i've compiled it and it shows that everything is okey. I'm really confused.

  #include <iostream>
using namespace std;
int n = 20;
int g(int n) {
 n = n+2;
 cout << n << ::n;
 return n;
}
int f(int n) {
 n = n+1;
 return n;;
}
int main()
{
int n = 17;
cout << g(n-1) + g(n+1);
cout << n << ::n;
return 0;
}

[jlb]

What does your "uni-test" actually say?

Perhaps the problem is the extra semi colon on line 11? Or perhaps the lack of any whitespace in your output? Or perhaps the lack of a consistent indentation style?

[specbk]

sorry, it means university test. I've done it last semester and i'm doing it again. The compiler doesn't take the extra semi colon as a mistake. According to the answer i got from my professor it is something within the "int g (int n)" function, but i still can't find out the problem.

[keskiverto]

Main types of errors:
* Syntax. Fails to compile.
* Logical errors. Program does not do what it should.

What is in lines 9-12? Nothing that would execute. Is that a logical error?

[jlb]

The code you posted is syntactically correct. Without knowing the parameters of the "test" I can only guess as to the problem.

Is this a program that you wrote for the test?

[specbk]

The type of the test is that we have different codes and we must type the answers that come out. The answer of the one i gave you is - "???" and that means there is some kind of a mistake within the code.
__________________________________________________________________
#include <iostream>
using namespace std;
int n = 20;
int g(int n) {
n = n+2;
cout << n << ::n;
return n;
}
int f(int n) {
n = n+1;
return n;;
}
int main()
{
int n = 17;
cout << f(n-1) + f(n+1);
cout << n << ::n;
return 0;
}

For an example this one is correct and it gives- 361720

[jlb]

Actually the output of the program you gave in the first snippet is: 18202020381720, which looks correct for the given values.

[Chervil]

How do we decide what should be the correct output? There needs to be some indication of what the program is supposed to be doing. Usually I'd consider it a problem to use cout << with a function which contains its own cout statement. That's not necessarily an error, but I'd suggest it would be a poor design - unless the specification called for it.

[specbk]

The idea is to give a correct output. I also get the same values from the first code. Is it possible that there is a mistake not in the code, but in the test answer given by the university?

[jlb]

Good question for your instructor I would say.

[booradley60]

I'm leaning toward Chervil's suggestion. Perhaps the cout line in the g function (line 6 in OP) should be removed. It would then at least have some symmetry with the f function that was invoked in your "working" example.

[specbk]

Thanks a lot for the help!!