Multiple functions problem

[whyunomad]

When i run it it says Program stopped working.

But i can't see what's the problem with the code. Does anyone know why is it giving an error ?


Here is the code:

#include <iostream>

using namespace std;

int f(int);
int h(int);
int g(int);

int g(int n)
{
    return g(0) == 0 ? 0 : (2 * f(n));
}
int f(int n)
{
    return f(0) == 0 ? 0 : (h(n) + g(n-1));
}
int h(int n)
{
    return h(0) == 0 ? 1 : (n *(h(n-1)));
}

int main()
{
    cout << f(3);
}

And this is the task i should solve with this code :

f(0) = 0
g(0) = 0
h(0) = 1
f(n) = h(n)+g(n-1)
g(n) = 2*f(n)
h(n) = n*h(n-1)

[Chervil]

Looks like recursion which never terminates.
What's the first thing that happens after function f() is called?

[whyunomad]

Looks like recursion which never terminates.
What's the first thing that happens after function f() is called?

It does h(n) + g(n-1)

[Chervil]

Not quite.

First of all it has to evaluate the condition (f(0) == 0) to determine whether it is true or false. As a result it calls function f() to find the value of f(0). Then it has to call f() again ...

If you have a debugger you can step through the code line by line, place a breakpoint in each function to see this.

Actually, I think the correct code might look like this,

int f(int n)
{
    return n == 0 ? 0 : (h(n) + g(n-1));
}

[whyunomad]

Oh okay, i see what you mean. The way i did it, it just does a endless loop. You are right ! Thanks so much for a quick response :)